ON THE COVER

On-specular (z direction) and offspecular (over the in-plane x-axis) 

neutron scattering measured with the 

AND/R reflectometer using a positionsensitive detector. In this experiment, 

columnar spin-valves having layers 

in the z-direction and an ellipsoidal 

cross-section (image, left) were made in 

a regular rectangular array on a silicon 

substrate. The in-plane Bragg peaks 

(sharp features) come from the repeat 

distance of the array, while the broader 

feature comes from a more local realspace structure, i.e., the micromagnetic 

structure of the individual spin valves 

averaged over many spin-valves. 

K. Krycka, et al., J. of Appl. Phys. 105, 

07C120 (2009).

NCNR 2009 Accomplishments and Opportunities

2009 NIST Center for 

Neutron Research

Accomplishments

and Opportunities

NIST Special Publication 1105

Robert M. Dimeo, Deputy Director

Ronald L. Cappelletti, Editor

December 2009

National Institute of Standards and Technology

Patrick Gallagher, Director

U.S. Department of Commerce

Gary Locke, Secretary
DISCLAIMER

Certain commercial entities, equipment, or materials may be identified

in this document in order to describe an experimental procedure or 

concept adequately. Such identification is not intended to imply

recommendation or endorsement by the National Institute of Standards

and Technology, nor is it intended to imply that the entities, materials,

or equipment are necessarily the best available for the purpose.

National Institute of Standards and Technology

Special Publications 1105

Natl. Inst. Stand. Technol. Spec. Publ. 1105, 88 pages

(December 2009)

CODEN: NSPUE2

U.S. GOVERNMENT PRINTING OFFICE-WASHINGTON: 2009

For sale by the Superintendent of Documents,

U.S. Government Printing Office

Internet: bookstore.gpo.gov Phone: 1.866.512.1800

Fax: 202.512.2104 Mail: Stop SSOP, Washington, DC 20402-0001
NCNR 2009 Accomplishments and Opportunities

iv. FOREWORD

1 THE NIST CENTER FOR NEUTRON RESEARCH

2 NIST CENTER FOR NEUTRON RESEARCH INSTRUMENTS

4 NCNR EXPANSION 2009 ACTIVITIES

6 NCNR IMAGES 2009

HIGHLIGHTS

CONDENSED MATTER

8 Antiferromagnetic Exchange Coupling in the Dilute 

Ferromagnetic Semiconductor GaMnAs, J.-H. Chung, et al.

10 Observation of Magnetic Monopoles in Spin Ice, H. 

Kadowaki, et al.

12 Magnetic and Structural Phase Diagram for the CeFeAsO1-xFx

High-temperature Superconductors, J. Zhao, et al.

14 Formulas Matter - Stoichiometry and Superconductivity in 

Fe1+δSe, T.M. McQueen, et al.

16 Iron-Arsenide Superconductors Under Pressure: The Unusual 

Case of CaFe2As2, A. Kreyssig, et al.

18 Key Role of Iron-Magnetism in High-temperature Fe-Pnictide 

Superconductors, T. Yildirim

BIOLOGY

20 How Does Cardiac Myosin Binding Protein C Help to 

Maintain a Healthy Heartbeat?, T.A. Whitten, et al.

22 How Do Lipid Membranes Accommodate Voltage-sensing 

Domains of Ion Channels?, M. Mihailescu, et al.

24 Control of Protein Structure and Function by Hydrodynamic 

Shear, S. Neelamegham, et al.

ENGINEERING

26 Neutron Measurements of Preferred Orientation and the 

Prediction of Forming Properties in Automotive Sheet 

Materials, T. Gnäupel-Herold, et al.

CHEMICAL PHYSICS

28 Water Dynamics in Hydrophobic Confinement, A. Faraone, 

et al.

30 Toward an Improved Understanding of Hydrogen Interactions 

with Coordinated Metals, C.M. Brown, et al.

32 Molecular Mobility and Ion Transport in Solid Polymer 

Electrolytes for Lithium Batteries, S.K. Fullerton, et al.

SOFT MATTER

34 Film Morphology of Polymer-based Solar Cells, J.W. Kiel, et al.

36 Engineering Protein Electrophoresis with the Aid of SANS, 

D. Pozzo, et al.

38 Organic Semiconductor Polymer Blends for Printable 

Electronics, D.M. DeLongchamp, et al.

40 A Compartmentalized Hydrogel from an ABC Block 

Terpolymer, R.R. Taribagil, et al.

42 Dynamics and Structure of Semiflexible, Self-assembled 

Peptide Chain Networks, M.C. Branco, et al.

44 Dynamics of Bio-membranes: Effects of Phospholipid 

Conformations and Presence of Local Anesthetics, Z. Yi, et al.

EARTH SCIENCE

46 Probing the Interface of Bedrock and Soil Using Scattered 

Neutrons, S.L. Brantley, et al.

INSTRUMENTATION

48 MACS -The Multi-axis Crystal Spectrometer, J.A. RodriguezRivera, et al.

ADVANCES IN MEASUREMENT

50 Are There Benefits to Multiple Beam Neutron Spectrometers? 

N.F. Berk, et al.

51 High Resolution Stress Measurements Using In-house X-ray 

Diffraction, T. Gnäupel-Herold, et al.

52 Neutron Tomography for Advanced Energy Storage, D.S. 

Hussey, et al.

53 A Phase-inversion Principle for Neutron Specular 

Reflectometry, N.F. Berk, et al.

54 NEUTRON SOURCE OPERATIONS

55 FACILITY DEVELOPMENT

58 SERVING THE SCIENCE AND TECHNOLOGY COMMUNITY

60 THE CENTER FOR HIGH RESOLUTION NEUTRON SCATTERING (CHRNS)

62 AWARDS 2008

64 PUBLICATIONS

80 INSTRUMENTS AND CONTACTS

CONTACTS (inside back cover)

Table of Contents
iv

Foreword

It is my pleasure to present to you the research accomplishments and opportunities for the 

NIST Center for Neutron Research for 2009. This has been a very exciting year and one 

of change. Pat Gallagher, NCNR Director since 2004, was appointed to NIST Deputy

Director in September 2008, and sworn in as NIST Director in November 2009. We have all

watched with great interest as Pat has taken on these new responsibilities where his significant 

leadership talents, which have been known well to all of us here at the NCNR, are now

appreciated by a much broader population. 

It is particularly exciting for me to witness daily the progress towards our Expansion Project. Since our last annual

report in 2008 our site has changed its appearance substantially with a great deal of the construction of our expanded 

cold neutron guide hall (GH) and technical support/administrative building (TSB) underway. As of this writing,

much of the steel and concrete work is complete in the TSB and the steel work is ready to begin on the expanded GH. I 

invite you to look at the photographs of the site as of August 2009 in this report. More details regarding progress on the

Expansion Project can be found in the section on Facility Developments. 

This was an outstanding year for reactor operations and engineering. The reactor operated for 242 days out of 246 

scheduled, with a reliability factor better than 98 %. The cold source availability during 2009 was more than 99 %. This 

availability is a testimony to our dedicated operations and engineering staff responsible for the day-to-day operations

and maintenance of the plant. Reliability has always been one of the most essential ingredients in running a successful 

user program. Perhaps the biggest news this year from reactor operations and engineering is on our re-licensing efforts. 

On July 2nd, the Nuclear Regulatory Commission presented us with a license to operate for another 20 years. Receipt of

this license is the culmination of NCNR efforts that began over ten years ago. The successful conclusion of this multiyear effort is due to numerous individuals and I am delighted that we have achieved this significant milestone.

 I am also delighted that Tawfik Raby, who retired this year, is being recognized by having his photograph placed in the 

NIST portrait gallery for his contributions for NBS/NIST. As Chief of Reactor Operations for many years, Tawfik left

the NCNR with a legacy of safe, reliable, and highly economical reactor operations. We all are indebted to him for his 

leadership and setting the highest standards for reactor operations.

As always, the reason for our operations is the neutron measurement capability that we offer to the scientific 

community. Our success as a national user facility is measured by scientific output enabled by these capabilities. The 

highlights found here are representative of the continued outstanding research performed at the NCNR. I have greatly 

enjoyed reading these highlights and I think that you will agree that the productivity and quality of the scientific output

continues to be exemplary.

I wish to extend my thanks to all who have contributed to an outstanding year!
NCNR 2009 Accomplishments and Opportunities 1

The NIST Center for Neutron Research

Neutrons provide a uniquely effective probe of the structure and 

dynamics of materials ranging from water adhering to clefts within 

proteins to magnetic domains in memory storage materials. The 

properties of neutrons (outlined below) can be exploited using a 

variety of measurement techniques to provide information not 

otherwise available. The positions of atomic nuclei in crystals, 

especially those of light atoms, can be determined precisely. 

Atomic motion can be directly measured and monitored as a 

function of temperature or pressure. Neutrons are especially 

sensitive to hydrogen, so that hydrogen motion can be followed 

in new H-storage materials and water take-up can be monitored 

as cement sets. Residual stresses such as those deep within oil 

pipelines or in highway trusses can be mapped. Neutron-based 

measurements contribute to a broad spectrum of activities 

including in engineering, materials development, polymer 

dynamics, chemical technology, medicine, and physics.

The NCNR’s neutron source provides the intense, conditioned 

beams of neutrons required for these types of measurements. In 

addition to the thermal neutron beams from the heavy water or 

graphite moderators, the NCNR has a large area liquid hydrogen 

moderator, or cold source, that provides long wavelength guided 

neutron beams for the major cold neutron facility in the U.S.

There are currently 29 experiment stations: four provide 

high neutron flux positions for irradiation, and 25 are beam 

facilities most of which are used for neutron scattering research. 

The subsequent pages provide a schematic description of our 

instruments. More complete descriptions can be found at www.

ncnr.nist.gov/instruments/. The NCNR is currently adding a 

second guide hall with five new instruments in a major expansion 

(see pp. 4–5).

The Center supports important NIST measurement needs, but 

is also operated as a major national user facility with meritbased access made available to the entire U.S. technological 

community. Each year, more than 2000 research participants 

from government, industry, and academia from all areas of 

the country use the facility. Beam time for research to be 

published in the open literature is without cost to the user, 

but full operating costs are recovered for proprietary research. 

Access is gained mainly through a web-based, peer-reviewed 

proposal system with user time allotted by a beamtime 

allocation committee twice a year. For details see www.ncnr.

nist.gov/beamtime.html. The National Science Foundation 

and NIST co-fund the Center for High Resolution Neutron 

Scattering (CHRNS) that operates six of the world’s most 

advanced instruments. Time on CHRNS instruments is made 

available through the proposal system. Some access to beam 

time for collaborative measurements with the NIST science 

staff can also be arranged on other instruments.

Why Neutrons?

Neutrons reveal properties not readily probed by photons or electrons. They are electrically 

neutral and therefore easily penetrate ordinary matter. They behave like microscopic magnets, 

propagate as waves, can set particles into motion losing or gaining energy and momentum in the 

process, and they can be absorbed with subsequent emission of radiation to uniquely fingerprint 

chemical elements.

WAVELENGTHS − in practice range from ≈ 0.01 nm (thermal) to ≈ 1.5 nm (cold) 

(1 nm = 10 Å), allowing the formation of observable interference patterns when scattered from 

structures as small as atoms to as large as cells. 

ENERGIES − of millielectronvolts, the same magnitude as atomic motions. Exchanges of energy 

as small as nanoelectronvolts and as large as tenths of electronvolts can be detected between 

samples and neutrons, allowing measurements in folding proteins, melting glasses and diffusing 

hydrogen.

SELECTIVITY − in scattering power varies from nucleus to nucleus somewhat randomly. Specific 

isotopes can stand out from other isotopes of the same kind of atom. Specific light atoms, difficult to observe with x-rays, are revealed 

by neutrons. Hydrogen, especially, can be distinguished from chemically equivalent deuterium, allowing a variety of powerful contrast 

techniques.

MAGNETISM − makes the neutron sensitive to the magnetic moments of both nuclei and electrons, allowing the structure and behavior of 

ordinary and exotic magnetic materials to be detailed precisely. 

NEUTRALITY − of the uncharged neutrons allows them to penetrate deeply without destroying samples, passing through walls that 

condition a sample’s environment, permitting measurements under extreme conditions of temperature and pressure.

CAPTURE − characteristic radiation emanating from specific nuclei capturing incident neutrons can be used to identify and quantify

minute amounts of elements in samples as diverse as ancient pottery shards and lake water pollutants.

Cold neutron Guide Hall and instruments. 

A second Guide Hall is under 

construction.
2NCNR Instruments

NIST Center for Neutron Research Instruments

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NCNR Expansion
NCNR 2009 Accomplishments and Opportunities 5

2009 Activities

UÊ Groundbreaking and construction 

of Technical Support Building and 

New Guide Hall

UÊ Instrumentation design and 

engineering in progress

UÊ Guides procured and delivery 

underway

UÊ Control Room upgrade procurement 

in progress
6NCNR Images 2009

NCNR Images 2009

Summer intern Pavan Bhargava setting up an x-ray 

measurement

NRC renews NCNR operating license for another 20 years Inauguration gathering of the MACS team in front of their 

instrument

Construction, August 21, 2009

Groundbreaking

Celebration

October 1, 2008

NCNR’s Steve Kline discusses a point with NCNR alumnus MuPing Nieh
NCNR 2009 Accomplishments and Opportunities 7

NCNR Dep. Dir. Robert Dimeo 

and NIST Dir. Patrick Gallagher 

at groundbreaking for NCNR 

expansion construction

Huagen

Peng of NIST 

Polymers Div. 

at a NG-7 

reflectometry

tutorial

NCNR’s Bill Clow and Elisabeth 

Carpenter place a sample into a toploading 3He cryostat

NCNR’s

Paul Butler 

points out a 

SANS result 

to Liliana 

Polo, Carlos 

Rinaldi, and 

Adriana

Herrera, all 

from UPRM

JHU student Vivek 

Thampy at the MAC 

console with NCNR’s 

Jose Rodriguez
8Condensed Matter

Magnetic data storage is a critical component

of modern electronic devices such as personal

computers and MP3 players. Current magnetic hard drives

that are based on metallic magnets can only hold data. Data 

must be sent on to a semiconductor device for processing. 

In principle, use of a ferromagnetic semiconductor would

make it possible for a single device to store data and

process it, facilitating faster and smaller electronic gadgets. 

Unfortunately, no suitable ferromagnetic semiconductors

are found in nature, causing researchers to focus on

artificial dilute magnetic semiconductors, most notably

semiconducting GaAs doped with magnetic Mn ions

at Ga sites. 

GaMnAs has been widely studied, and it has been

convincingly established that it exhibits ferromagnetism

mediated by itinerant holes. For thin layers of metallic

ferromagnets separated by non-magnetic layers, carriermediated magnetic exchange can lead to spontaneous,

anti-parallel alignment of the magnetizations of

neighboring ferromagnetic layers. This phenomenon is

known as antiferromagnetic exchange coupling, and is an 

extremely useful property in multilayer devices. If the layers

spontaneously align antiparallel, they can be switched into 

parallel alignment via an applied magnetic field, which 

in turn can drastically affect the electrical conductivity of

the stack (i.e., the giant magnetoresistive effect). It has 

long been theoretically predicted that its carrier-mediated 

ferromagnetism should also make antiferromagnetic 

interlayer exchange coupling possible for GaMnAs [3], but 

it had never previously been experimentally demonstrated. 

Neutron scattering has been used to demonstrate for

the first time that thin layers of the dilute magnetic

semiconductor GaMnAs can exhibit antiferromagnetic

interlayer exchange coupling [1,2], a discovery that helps

pave the way for novel new “spintronic” devices, and

deepens our understanding of this important class of

materials. 

To study this phenomenon, we used molecular beam 

epitaxy to grow two different multilayer samples, both 

comprised of ten layers of 6.95 nm Ga0.97Mn0.03As, each separated

by a 3.47 nm non-magnetic spacer layer, with an extra GaAs 

capping layer at the top. For the control sample, the spacer layers 

were pure GaAs. For the other sample, the spacer layers were

GaAs doped with 1.2x1020 cm-3

 of Be. The Be is non-magnetic

but adds holes to the spacer layer, and thus plays a role in the

carrier-mediated ferromagnetism of the GaMnAs layers. A cartoon 

depicting the Be-doped sample is shown in Fig. 1. 

FIGURE 1: Cartoon depicting the Be-doped sample. Polarized neutron beams 

(long arrows) are sensitive to the properties of the individual layers in the 

multilayer stack, allowing us to demonstrate hole-mediated, antiferromagnetic 

interlayer exchange coupling among the GaMnAs layers.

The temperature-dependent magnetizations of the two samples

were measured in the presence of several different magnetic fields 

using superconducting quantum interference device magnetometry

(Fig. 2). For the undoped spacer sample (Fig. 2a), a smooth

reduction in magnetization with temperature is observed for all

fields studied. This is also the case for the Be-doped spacer sample 

(Fig. 2b) at higher fields (10 mT to 50 mT). However, for very 

small fields, (< 4 mT) a “hitch” is observed at about 40 K. This 

feature is consistent with a competition between an interlayer

exchange coupling that promotes anti-parallel alignment of the 

GaMnAs magnetizations, and the applied magnetic field that 

promotes parallel alignment. However, this conjecture cannot be 

Antiferromagnetic Exchange Coupling in the Dilute 

Ferromagnetic Semiconductor GaMnAs

J.-H. Chung1, S.J. Chung1, and S.Lee1, B.J. Kirby2, J.A. Borchers2, Y.J. Cho3, X. Liu3,

and J.K. Furdyna3

Korea University, Seoul 136-713, Korea 2

NIST Center For Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 3

University of Notre Dame, Notre Dame, Indiana 46556
NCNR 2009 Accomplishments and Opportunities 9

proven through magnetometry alone, which is sensitive only to the 

collective magnetic response of the entire multilayer sample. 

FIGURE 2: Temperature-dependent magnetizations for the undoped spacer 

sample (a) and the Be-doped spacer sample (b). From Ref. 1.

Thus, to study the samples we used polarized neutron reflectometry 

(PNR), a technique sensitive to the structural and magnetic depth 

profiles of thin films and multilayers. Figure 3 shows reflectivities 

as a function of scattering vector Q for the samples taken at 

characteristic conditions after cooling from room temperature in 

zero field. Unpolarized beam reflectivity for the Be-doped sample, 

taken in zero field at 100 K is shown at top (black). As 100 K is 

well above the ferromagnetic transition temperature, these data 

corresponds purely to the nuclear depth profile of the multilayer 

stack. A superlattice Bragg feature can be seen at 0.062 Å-1, 

indicative of the repeating {6.97 nm GaMnAs / 3.47 nm GaBeAs} 

structure (note, the presence of an S-shaped “Bragg feature” instead 

of a classic Bragg peak is consequence of symmetry-breaking due 

to the capping layer). The second set of data from the top is of 

polarized beam, non spin-flip, spin-up (blue) and spin-down 

(red) reflectivities taken after cooling to 7 K and applying a 

1.5 mT field. The structural Bragg feature is present in the 

same first order position in both channels, but an additional 

spin-split feature is also present at the half order position of the 

superlattice (i.e., at ≈ 0.03 Å-1, corresponding to two GaMnAs/

GaBeAs repeats). Model fitting confirms that this feature is 

evidence of antiparallel alignment of alternating GaMnAs layer 

magnetizations, and is therefore evidence of antiferromagnetic 

exchange coupling among the layers. 

When the applied field is increased to 100 mT (Fig. 3, third set of 

curves from the top), the half order Bragg feature disappears, and 

the first order Bragg feature becomes spin-split, indicating that the 

applied field dominates the intrinsic interlayer coupling and pulls 

the GaMnAs layer magnetizations into parallel alignment. At 

these low temperatures, crystalline anisotropy prevents a return to 

anitferromagnetic order when the field is reduced back to 1.5 mT. 

However, if the anisotropy is weakened by raising the temperature 

to 30 K, exchange coupling can dominate, and antiferromagnetic 

order does return after field cycling (not shown), demonstrating 

the robustness of this effect. The bottom of Fig. 3 shows polarized 

beam data for the un-doped spacer sample, after cooling from 

room temperature to 7 K in zero field and then applying 1.5 mT. 

For this sample we see no half order Bragg feature, and a spin-split 

first order Bragg feature, indicating spontaneous parallel alignment 

of the GaMnAs layer magnetizations. Since the nature of the 

coupling is observed to be dependent on the Be concentration, and 

thereby dependent on the hole concentration, we can conclude 

that the exchange coupling between GaMnAs layers is indeed a 

carrier mediated effect. 

FIGURE 3: Neutron reflectivities for the the undoped and Be-doped samples 

taken under selected conditions. Different data sets are offset for clarity.

This work demonstrates that structures comprised of this 

important ferromagnetic semiconductor can be made to exhibit 

ferromagnetic/antiferromagnetic switching in response to an 

applied magnetic field, a property that should prove important in 

potential device applications. 

References

[1] J.-H. Chung, S. J. Chung, Sanghoon Lee, B.J. Kirby, J.A. Borchers, 

Y.J. Cho, X. Liu, and J.K. Furdyna, Phys. Rev. Lett. 101, 237202 

(2008).

[2] S. Lee, J.-H. Chung, X. Liu, J.K. Furdyna, and B.J. Kirby, Materials 

Today 12, 14 (2009).

[3] T. Jungwirth, W.A. Atkinson, B.H. Lee, and A.H. MacDonald, 

Phys. Rev. B 59, 9818 (1999).
10Condensed Matter

From the symmetry of Maxwell’s equations of

electromagnetism, magnetic charges or monopoles

would be expected to exist in parallel with electric charges. 

Moving electric charges produce magnetic fields, and 

moving magnetic charges would then produce electric fields. 

The quantum mechanical hypothesis of the existence of

magnetic monopoles was originally proposed by Dirac [1], 

and in current theories monopoles are predicted in grand

unified theories as topological defects in the energy range of 

the order 1016GeV [3]. These enormous energies preclude 

all hope of creating them in laboratory experiments, and

magnetic monopoles have never been observed despite

longstanding experimental searches [2]. Consequently,

attention has turned to condensed matter systems where

tractable analogs of magnetic monopoles might be found, 

and one prediction is for an emergent elementary excitation 

in the spin ice compound Dy2Ti2O7, where the strongly

competing magnetic interactions exhibit the same type of 

frustration as water ice [3]. We have successfully observed 

the signature of magnetic monopoles in spin ice using 

neutron scattering, and find that they interact via the

magnetic inverse-square law force. In addition, specific 

heat measurements show that the density of monopoles can

be controlled by temperature and magnetic field, with the 

density following the expected Arrhenius law [4].

In H20 ice, the protons are disordered even at absolute zero

temperature and thus retain finite entropy, and spin ice is a

magnetic material that exhibits the same type of disordered

ground state. Here the Dy spins occupy a cubic pyrochlore 

lattice, which is a corner sharing network of tetrahedra. 

The strongly competing magnetic interactions cannot

all be satisfied, resulting in a frustrated magnetic ground 

state as shown in Fig. 1a, where each spin is parallel to a 

local [111] easy axis and interacts with neighboring spins

via an effective ferromagnetic coupling. Then the lowest

energy spin configurations on each tetrahedron follow the 

ice rule, in which two spins point inward and two point

outward. There are six equivalent ways of arranging this 

Observation of Magnetic Monopoles in Spin Ice

H. Kadowaki,1 N. Doi,1 Y. Aoki,1 Y. Tabata,2 T.J. Sato,3 J.W. Lynn,4 K. Matsuhira,5 Z. Hiroi6

1

Tokyo Metropolitan University, Hachioji-shi, Tokyo 192-0397, Japan 2

Kyoto University, Kyoto 606-8501, Japan 3

NSL, Institute for Solid State Physics, University of Tokyo, Tokai, Ibaraki 319-1106, Japan 4

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 5

Kyushu Institute of Technology, Kitakyushu 804-8550, Japan 6

Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan

“2-in, 2-out” ground state spin structure on each tetrahedron,

and the possible ground states of the entire tetrahedral network

are macroscopically degenerate in the same way as the disordered

protons in ice. In addition to this remarkable observation, there

is the more intriguing possibility that the excitations from these

highly degenerate ground states are topological in nature and 

mathematically equivalent to magnetic monopoles [3].

FIGURE 1: Magnetic moments of Dy2Ti2O7 reside on the corners of 

tetrahedra of the cubic pyrochlore lattice. They are represented by arrows 

pointing inward or outward from centers of the tetrahedra. Four magnetic 

moments on each tetrahedron obey the ice rule (2-in, 2-out) to minimize the 

effective ferromagnetic interaction. The resulting spin ice state consists of 

a macroscopic number of disordered configurations, an example of which 

is shown in (a). The pyrochlore lattice consists of stacked triangular and 

kagomé lattices, shown by green and blue lines, respectively, along a [111] 

direction. (b) Under small [111] magnetic fields, spins on the triangular lattices 

become parallel to the field and drop out of the problem, while the spins on 

the kagomé lattice remain in the disordered kagomé ice state. (c) An excited 

state is induced by flipping a spin from (b), enclosed by a dashed circle, 

where neighboring tetrahedra have 3-in, 1-out and 1-in, 3-out configurations. 

These ice-rule-breaking tetrahedra are represented by magnetic monopoles 

with opposite charges depicted by blue and red spheres. (d) By consecutively 

flipping two spins from (c), the monopoles are fractionalized. (e) At high 

magnetic fields (H »Hc) spins realize a fully ordered, staggered arrangement 

of monopoles.

The macroscopic degeneracy of the spin ice state can be simplified 

by applying a small magnetic field along a [111] direction,

producing the kagomé ice state (Fig. 1b) that serves as our initial 

“vacuum” state for the creation of magnetic monopoles. An

excitation then is generated by flipping a spin on the kagomé 

lattice, which results in ice-rule-breaking “3-in, 1-out” (magnetic

monopole) and “1- in, 3-out” (anti-monopole) tetrahedral

neighbors, as shown in Fig. 1c. The ice-rule-breaking tetrahedra 

simulate magnetic monopoles, with net positive and negative

charges sitting on the centers of tetrahedra. The monopoles should 
NCNR 2009 Accomplishments and Opportunities 11

interact via the magnetic inverse-square law force, which is brought 

about by the dipolar interaction between spins. The monopoles 

can move and separate by consecutively flipping spins, but are 

confined to the two-dimensional kagomé layer (e.g., Fig. 1d). This 

possibility of separating the local excitation into its constituent 

parts is a novel fractionalization in a frustrated system, and enables 

many new aspects of these emergent excitations to be studied 

experimentally, such as pair creation and interaction, individual 

motion, currents of monopoles and their concomitant electric 

field, correlations, and cooperative phenomena.

In the neutron measurements, one challenge is to distinguish the 

relatively weak monopole scattering from the very strong magnetic 

scattering of the ground state ‘vacuum’. The best temperature and 

field region to observe monopoles in Dy2Ti2O7 is close to the 

liquid-gas type critical point (Tc, Hc) shown in the inset of Fig. 2. 

The data in Fig. 2 show the field dependence of the magnetic 

intensity of the (2,-2,0) Bragg reflection at T = Tc + 0.05 = 0.43 K. 

The intensity plateau for μ0H < 0.8 T corresponds to the kagomé 

ice state with a low density of monopoles (Fig. 1b). The deviation 

from the plateau as μ0H exceeds 0.8 T indicates that monopoles 

are being created gradually, while the saturation of the intensity for 

H » Hc denotes the staggered monopole state (Fig. 1e) where every 

tetrahedron contains a monopole. The Bragg intensity data are 

compared with (MC) simulations for the dipolar spin ice model to 

quantify our observations, and the overall agreement is very good. 

FIGURE 2: The magnetic Bragg intensity at T = Tc + 0.05 K is plotted as 

a function of the [111] magnetic field strength. The open squares and 

dashed curves represent the neutron scattering measurements at (2,-2,0) 

and corresponding MC simulations, respectively. The dot-dashed curve is 

the density of positively charged monopoles obtained by the MC simulation. 

(Inset) The H,T phase diagram for a [111] magnetic field. The solid line 

represents the first-order phase transition with the critical point shown by an 

open circle. The dashed lines are crossovers. The intensity maps shown in 

Fig. 3 were measured at the two points depicted by open squares.

Intensity maps for the diffuse monopole scattering and for the 

kagomé ice state at T = Tc+ 0.05 K and μ0H = 0.5 T are shown 

in Fig. 3. The observed scattering pattern of the kagomé ice 

state (Fig. 3a) is in excellent agreement with the MC simulations 

(Fig. 3c), showing the peaked structure at (2/3,-2/3,0) and the 

pinch point at (4/3,-2/3,-2/3). These structures reflect the vacuum 

kagomé ice state. The intensity map for the diffuse scattering 

around (2,-2,0) associated with the scattering by the separated 

monopoles is shown in Fig. 3b. The data agree quite well with the 

MC simulation shown in Fig. 3d. An interesting experimental fact 

is that correlations of the monopoles in the high-density regime are 

three dimensional in space, although the monopoles can only move 

in the two dimensional layers (Fig. 1d). The three dimensional 

correlations provide strong evidence that the magnetic inversesquare law interaction really acts between monopoles in all three 

dimensions.

FIGURE 3: Intensity maps of neutron scattering measured at T = Tc + 0.05 K 

are shown for the two field-temperature values indicated in the inset of Fig. 

2. The kagomé ice state at μ0H = 0.5 T (a) compared with the MC simulations 

(c), and the weakened kagomé ice state scattering plus the diffuse monopole 

scattering (b) and MC simulations (d) H = Hc.

Typical elementary excitations in condensed matter, such as 

acoustic phonons and (gapless) magnons, are Nambu-Goldstone 

modes where a continuous symmetry is spontaneously broken 

when the ordered state is formed. This behavior contrasts 

with the monopoles in spin ice, which are point defects that 

can be fractionalized in the frustrated ground states. Such 

excitations are unprecedented in condensed matter, and will now 

enable conceptually new emergent phenomena to be explored 

experimentally.

References

[1] P. A. M. Dirac, Proc. Royal Soc. 133, 60 (1931).

[2] K. A. Milton, Rep. Prog. Phys. 69, 1637 (2006).

[3] C. Castelnovo, R. Moessner, and S. L. Sondhi, Nature 451, 42 

(2008).

[4] H. Kadowaki, N. Doi, Y. Aoki, Y. Tabata, T.J. Sato, J.W. Lynn, K. 

Matsuhira and Z. Hiroi, J. Phys. Soc. Jpn. 78, 103706 (2009).
12Condensed Matter

The nature of the magnetic order and spin fluctuations

in superconductors has had a rich and interesting 

history, and has been a topic of special interest ever since 

the parent materials of the high Tc cuprates were found to

be antiferromagnetic (AFM) Mott insulators that exhibit

huge exchange energies within the Cu-O planes. The parent 

materials of the newly discovered iron-based superconductors

are also energetic antiferromagnets with a layered crystal 

structure like the cuprates. However, they are not nearly 

as two-dimensional in character, which is an important 

advantage for applications such as power transmission lines

and energy storage. In the superconducting regime, both

classes of high Tc superconductors retain these energetic

spin correlations, and it is clear that they are involved in an

intimate way in the formation of the superconducting state 

[1]. Therefore it is critically important to understand how 

this transformation from magnet to high Tc superconductor

is accomplished. We have carried out a systematic

investigation of the magnetic and structural properties of

CeFeAsO1-xFx as the system is doped with fluorine (F) into 

the superconducting regime to elucidate these issues [2].

The parent iron oxypnictide materials such as LaFeAsO [3]

and CeFeAsO are metals and have a tetragonal crystal

structure at room temperature, but undergo a structural 

distortion to an orthorhombic phase around 155 K and 

develop long range antiferromagnetic order of the Fe 

spins below 140 K [3]. As oxygen is replaced by fluorine, 

electrons are doped into the parent compound, and both 

the structural and magnetic transitions decrease with 

increasing F concentration, x. The magnetic structure

remains commensurate and long range in nature with doping,

while the ordered moment and Néel temperature TN(Fe)

decrease rapidly with increasing x and vanish near x = 0.06, 

before the emergence of superconductivity for x > 0.06. 

This indicates that the superconducting and magnetic order

parameters compete with each other, and the overall behavior

is remarkably similar to that of the electron-doped high-Tc

copper oxides. The phase diagram as a function of fluorine

doping is shown in Fig. 1.

FIGURE 1: The structural and magnetic phase diagram determined from the 

neutron diffraction measurements on CeFeAsO1-xFx. The red circles indicate 

the onset temperature Ts of the tetragonal P4/nmm to orthorhombic Cmma 

phase transition. The black squares and green triangles designate the Néel 

temperatures of Fe TN(Fe) and Ce TN(Ce), respectively. The superconducting 

transition temperatures are from the onset Tc of the resistivity measurements.

The open triangles are Tc determined from susceptibility measurements. The 

inset shows the ordered antiferromagnetic moment as a function of F doping.

The structural phase transition temperature decreases more

gradually with increasing F doping and disappears around 

x = 0.1 when superconductivity is already well developed. It is

important to establish unambiguously that the superconducting

state can form equally in the tetragonal to orthorhombic structural

phases in CeFeAsO1-xFx. We therefore carried out additional 

measurements on the x = 0.08, 0.10 samples, above x = 0.06, which

have superconducting transitions of 27 K and 33 K, respectively. 

The tetragonal to orthorhombic phase transition temperature

was determined to be 60 K for x = 0.08, making it clear that the

orthorhombic phase is superconducting. No indication of a 

structural transition was evident for the x = 0.10 sample, indicating 

that this composition is at the terminus of the T-O structural 

phase boundary. Therefore, superconductivity in CeFeAsO1-xFx

can take place in either the low-temperature tetragonal or 

orthorhombic crystal structure. No evidence of static long range 

AFM Fe ordering was evident in either of these samples.

Magnetic and Structural Phase Diagram for the CeFeAsO1-xFx High 

Temperature Superconductors

J. Zhao1, Q. Huang2, C. de la Cruz1,3, S. Li1, J.W. Lynn2, Y. Chen2,4, M.A. Green2,4, G.F. Chen5,

G. Li5, Z. Li5, J. L. Luo5, N.L. Wang5, and P. Dai1,3

1

University of Tennessee, Knoxville, Tennessee 37996-1200 2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899

3

Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 4

University of Maryland, College Park, Maryland 20742 5

Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
NCNR 2009 Accomplishments and Opportunities 13

Undoped CeFeAsO has an orthorhombic low-temperature 

structure with c > a > b. Doping with F gradually reduces both 

the a (the long Fe-Fe nearest-neighbor distance) and c-axis lattice 

constants while leaving the b-axis (the short Fe-Fe nearest-neighbor 

distance) essentially unchanged. The orthorhombic distortion is 

quite small for x = 0.08, while the c-axis lattice constant decreases 

systematically with increasing doping for x > 0.10. The reduction 

in the c-axis lattice constant is achieved via a large reduction of the 

Ce-As distance, while the Ce-O/F and As-Fe-As block distances 

actually increase with increasing F-doping. This suggests that the 

effect of F doping is to bring the Ce-O/F charge transfer layer 

closer to the superconducting As-Fe-As block, thereby facilitating 

electron transfer. The Fe-As distance (2.405 Å) is found to be 

essentially independent of x, so that the strong hybridization 

between the Fe 3d and the As 4p orbitals is not affected by 

electron-doping. On the other hand, the Fe-Fe nearest-neighbor 

(J1) and next-nearest-neighbor (J2) effective exchange couplings 

are mediated through the electron Fe-As-Fe hopping and are 

controlled by the Fe-As-Fe angles, which are strongly x dependent.

FIGURE 2: Fe-As(P)-Fe bond angles, Fe-Fe, and Fe-As(P) distances for different 

Fe-based superconductors. There is a systematic decrease in the Fe-As(P)-Fe 

bond angle for Fe-based superconductors with higher Tc, suggesting that the 

lattice effects are important. a) Schematic illustration of what happens to the 

Fe-As-Fe tetrahedron for Fe-based superconductors as a function of increasing 

Tc. b,c) Dependence of the maximum-Tc on Fe-As(P)-Fe angle and Fe-Fe/FeAs(P) distance. The maximum Tc is obtained when the Fe-As(P)-Fe bond angle 

reaches the ideal value of 109.47° for the perfect Fe-As tetrahedron.

Comparison of the structural evolution of CeFeAsO1-xFx with 

other rare-earth Fe pnictides and with (Ba1-xKx)Fe2As2 has 

revealed a general trend that the Fe-As-Fe bond angle decreases 

systematically for materials with increasing Tc. This result suggests 

that the structural perfection of the Fe-As tetrahedron plays a 

crucial role for the superconducting pairing in these high-Tc Fe 

pnictides. In particular, the exchange couplings (J1 and J2) are 

directly related to the Fe-As-Fe bond angles, shown in Fig. 2a. 

Figures 2b and 2c plot the Fe-As(P)-Fe angles and Fe-Fe/Fe-As(P) 

distances versus the maximum Tc for different Fe-based rare-earth 

oxypnictides and Ba1-xKxFe2As2 superconductors. While the 

Fe-Fe/Fe-As(P) distances don’t appear to have a clear trend 

amongst different Fe-based superconductors, we find the 

remarkable result that the maximum Tc is directly related to the 

Fe-As(P)-Fe angles for a variety of materials as shown in Fig. 2c. 

In particular, the highest Tc is obtained when the Fe-As(P)-Fe 

angle reaches the ideal value of 109.47°

 for the perfect Fe-As 

tetrahedron. This suggests that the general way to increase Tc in 

the Fe-based superconductors is to reduce the deviation of the 

Fe-As(P)-Fe bond angle from the ideal Fe-As tetrahedron.

In summary, we have mapped out the structural and magnetic 

phase transitions of CeFeAsO1-xFx and found that the Fe long 

range antiferromagnetic order vanishes before the appearance 

of superconductivity. The phase diagram of CeFeAsO1-xFx is 

therefore remarkably similar to that of the electron-doped highTc copper oxides. The superconducting state, on the other hand, 

can form in both the orthorhombic and tetragonal structures. In 

addition to suppressing the static antiferromagnetism and inducing 

superconductivity, F doping also reduces the long-axis of the 

orthorhombic structure and decreases the Fe-As-Fe bond angles. 

We found that the Fe-As(P)-Fe bond angle plays a key role for the 

superconductivity, with Tc reaching its maximum value for the 

ideal Fe-As tetrahedral angle. Thus the distortion from the ideal 

Fe-As tetrahedron must be taken into account as we consider a 

mechanism for the high-Tc superconductivity in these Fe-based 

materials.

References

[1] J.W. Lynn and P. Dai, Physica C 469, 469 (2009).

[2] J. Zhao, Q. Huang, C. de al Cruz, S. Li, J. W. Lynn, Y. Chen, M. A. 

Green, G. F. Chen, G. Li, Z. C. Li, J. L. Luo, N. L. Wang, and P. Dai, 

Nature Materials 7, 953 (2008).

[3] C. de la Cruz, Q. Huang, J. W. Lynn, J. Li, W. Ratcliff II, J. L. 

Zarestky, H. A. Mook, G. F. Chen, J. L. Luo, N. L. Wang, and P. Dai, 

Nature 453, 899 (2008).
14Condensed Matter

Because iron is best known as the element that most 

often leads to high temperature ferromagnetism, the 

discovery of superconductivity in 2008 [1] in fluorine

doped lanthanum iron arsenide oxide (LaFeAsO), with the

high onset temperature of 26 K, came as a surprise to the 

materials physics community. This compound gave rise to

a new chemical family of superconductors, based on Fe2X2

(X = P,As) layers of edge-sharing FeX4 tetrahedra, now 

including oxygen-free systems and complex layered phases of

various types. In all cases the materials are difficult to make,

and involve reactive, volatile elements whose chemistry is

difficult to control. Important discrepancies therefore arise

between the formulas that researchers assume their materials 

have, and those they actually do have. 

In the process of investigating these compounds,

superconductivity was discovered at 8 K in chemically

analogous FeSe in its tetragonal form [2]. The Fe2Se2 layers

in this compound are analogous to the Fe2As2 and Fe2P2

layers in the pnictide and oxypnictide superconductors.

The initial report attributed the superconductivity to a 

highly selenium deficient phase, FeSe0.82 (i.e., Fe1.22Se). This

was quickly followed by a structural study that arrived at a 

composition of FeSe0.92 (Fe1.09Se) for the superconductor. 

Both of these formulas fall well outside the narrow

composition range, Fe1.01Se-Fe1.04Se, reported for the

tetragonal form of “FeSe” more than thirty years ago [3]. 

Thus, what appeared at first to be the simplest of the new

family of superconductors, holding out the hope that its 

study might lead to the determination of unambiguous

structure-formula-property relations, seemed to be different 

compounds in different laboratories. It was due to this 

problem that we took up the case of determining the 

formula of the “FeSe” superconductor.

Our initial attempts to prepare phase-pure superconducting

FeSe employed the methods typically employed in this field, 

starting with ‘freshly cleaned’ Fe powder. In agreement with 

others, we found that a significant amount of iron in excess

of the ideal 1:1 ratio, in our case Fe1.06Se, was needed to 

make a sample that appeared to be “phase pure” by laboratory x-ray

diffraction (XRD). Our initial neutron powder diffraction (NPD) 

characterization of these samples on the NIST high resolution

powder neutron diffractometer BT-1, showed, however, that they

were strongly multiple phase, with a substantial amount of iron oxide 

present, forcing us to reconsider the synthetic method employed. 

When prepared from very clean starting materials, specifically taking

care to exclude oxygen, to include steps and reactants specifically 

designed to remove any fortuitous oxygen from the synthetic system,

protecting the synthetic system from in-situ oxygen leaks, and

quenching the products to avoid low temperature decomposition, 

we found in contrast to the materials physics researchers that the 

formula of single phase material is Fe1.01Se. 

FIGURE 1: Rietveld refinement of 298 K BT-1 powder neutron diffraction 

data of Fe1.01Se annealed at 300 °C. The left inset shows the fit statistic Rwp

plotted versus Fe-interstitals (left) and Se-vacancies (right). From these data 

it is not possible to determine the origin of the 1 % non-stoichiometry, but 

this shows that the formula of superconducting “FeSe” must be within ≈ 2 % 

of stoichiometric. The right inset shows the structure of the superconducting 

phase.

The formula of the superconducting FeSe phase was confirmed

to be nearly stoichiometric by Rietveld refinements of the NPD 

data collected on BT-1. When freely refined, the composition of

the superconducting phase is nearly stoichiometric, in agreement

with our chemical equilibrium studies. To best determine the

Formulas Matter - Stoichiometry and Superconductivity in Fe1+δSe

T.M. McQueen1, Q. Huang2, V. Ksenofontov3, C. Felser3, Q. Xu4, H. Zandbergen4, Y.S. Hor1,

J. Allred1, A.J. Williams1, D. Qu5, J. Checkelsky5, N.P. Ong5 and R.J. Cava1

1

Department of Chemistry, Princeton University, Princeton NJ 08544 2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899

3

Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität, Staudinger Weg 9, D-55099, Mainz, Germany 4

Department of Nanoscience, TU Delft, The Netherlands 5

Department of Physics, Princeton University, Princeton NJ 08544
NCNR 2009 Accomplishments and Opportunities 15

stoichiometry and to see if we could locate the origin of any nonstoichiometry, we performed free fits to the data as a function 

of fixed doping levels, with excess iron in interstitial sites and 

with selenium vacancies. The refinement agreement statistics 

Rwp (minimum for the best agreement) for those refinements as 

a function of hypothetical stoichiometry are plotted in the inset 

to Fig. 1. The best agreement is centered at the stoichiometric 

FeSe composition, with the breadth of the minimum indicating a 

composition of Fe1.01±0.02Se. Thus, although these measurements do 

not have sufficient sensitivity to determine the stoichiometry to 

better than ± 0.02, the nearly ideal formula of the superconducting 

FeSe phase is clearly confirmed. 

FIGURE 2: (a) Dependence of superconducting transition temperature (Tc) on 

the crystallographic c/a ratio. The inset shows the dependence of c/a ratio on 

synthesis temperature and nominal composition. (b) Phase diagram derived 

from the samples shown in (a) and others (not shown). Actual compositions 

of the samples were estimated from the fraction of impurity phases present 

(Fe7Se8 and Fe metal) by XRD and/or room temperature M(H) curves. Below 

300 °C, the tetragonal form of Fe1+δSe, within which superconductivity occurs, 

slowly converts to the hexagonal NiAs form, which is not superconducting.

Further detailed synthesis and analysis studies indicate that the 

superconductivity, the formula, the synthesis conditions, and 

the crystal structure are correlated in the “FeSe” phase in an 

extremely sensitive manner. Fig. 2(a) shows the superconducting 

transition temperature Tc versus the crystallographic c/a ratio 

(the ratio of intraplane and interplane lattice parameters) for a 

number of the samples in this system. Several features are evident. 

Samples prepared at lower temperatures or with lower iron 

content display c/a ratios just above 1.464 and also display the 

highest superconducting transition temperatures. Higher iron 

contents or higher synthesis temperatures yield larger c/a ratios 

and reduced Tc’s. Samples prepared with the highest iron content, 

Fe1.03Se, show no superconductivity to 0.6 K, irrespective of the 

synthesis temperature. These samples also display abnormally small 

c/a ratios, near 1.461. Two distinct structure/superconductivity 

regions are therefore clearly seen in Fig. 2(a). The inset of Fig. 2(a) 

shows the dependence of the c/a ratio on starting composition 

for two representative preparation temperatures. In both 

cases, c/a initially rises with increasing Fe content, but by the 

composition Fe1.03Se the c/a ratio is much reduced. We postulate 

that this peculiar dependence of c/a ratio on iron content and 

the accompanying dramatic disappearance of superconductivity 

for Fe1.03Se are due to a change in how the non-stoichiometry is 

accommodated in the phase. Subtle differences in the structure 

therefore indicate that there is likely a difference in defect 

chemistry between superconducting and non-superconducting 

compositions. On the basis of these experiments, we construct 

the detailed phase diagram for the Fe-Se system near the 1:1 

stoichiometry in Fig. 2(b). 

The extreme sensitivity of structure and properties to the formula 

of the “FeSe” superconductor likely extends to other members 

of this family, and may explain conflicting reports about the 

properties in other much more problematic members of this 

superconducting family. Our study clearly shows that careful 

solid state chemistry and structural analysis can play an important 

role in the study of the structure/property relations in complex 

materials. 

References

[1] Y. Kamihara, T. Watanabe, M. Hirano, and H. Hosono, Journal of 

the American Chemical Society 130, 3296 (2008). 

[2] F. C. Hsu, J. Y. Luo, K. W. Yeh, T. K. Chen, T. W. Huang, P. M. 

Wu, Y. C. Lee, Y. L. Huang, Y. Y. Chu, D. C. Yan, and M. K. Wu, 

Proceedings of the National Academy of Sciences 105, 14262 (2008).

[3] W. Schuster, H. Mikler, and K. L. Komarek, Monatshefte Fur 

Chemie 110, 1153 (1979). 

[4] T.M. McQueen, Q. Huang, V. Ksenofontov, C. Felser, Q. Xu, H. 

Zandbergen, Y.S. Hor, J. Allred, A.J. Williams, D. Qu, J. Checkelsky, 

N.P. Ong, R.J. Cava, Phys. Rev. B 79, 01452 (2009).
16Condensed Matter

Two recently discovered families of high transition temperature (high Tc) superconductors originate from

the parent systems RFeAsO (R = rare earth) and AFe2As2

(A = alkaline earth metal). The parent compounds are

not superconducting at ambient pressure, while chemical

doping results in a superconducting transition as high as 

55 K in RFeAsO1-xFx and 38 K in A1-xKxFe2As2. Much of 

the excitement surrounding these new superconductors is

that they offer yet another route to high superconducting

transition temperatures, because the ubiquitous copperoxygen planes found in the older high Tc superconductors,

the cuprates, are absent. The RFeAsO and AFe2As2

families are tetragonal at room temperature but undergo 

an orthorhombic distortion in the range 100 K to 220 K

that is associated with the onset of antiferromagnetic order

(see Fig. 1). Tuning the system via element substitution

or oxygen deficiency suppresses the magnetic order and 

structural distortion in favor of superconductivity, with a

phase diagram strikingly similar to the high-Tccopper oxide 

family of superconductors. In particular, strong magnetic 

correlations persist in the superconducting regime, and a 

magnetic resonance forms below Tc, demonstrating that

magnetism is intimately tied to the superconducting state.

FIGURE 1: Illustration of the crystal structure of CaFe2As2, and the 

antiferromagnetic structure below the structural/magnetic transition. 

The magnetic unit cell is the same as the orthorhombic chemical unit 

cell. The Fe moments are oriented along the orthorhombic a axis.

In the AFe2As2 (A=Ba,Sr,Ca) family it was reported that 

the parent compounds themselves become superconducting

with Tc as high as 28 K in BaFe2As2 and SrFe2As2, and 12 K

Iron-Arsenide Superconductors Under Pressure:

The Unusual Case of CaFe2As2

A. Kreyssig1, D.K. Pratt1, S. Nandi1, Y.B. Lee1, G.D. Samolyuk1, N. Ni1, S.L. Bud’ko1,

B.N. Harmon1, P.C. Canfield1, R.J. McQueeney1, A.I. Goldman1, M.A. Green2, P. Zajdel2, Y. Chen2,

J.B. Leão2, S.J. Poulton2, J.W. Lynn2

, K. Prokeš3, S.A.J. Kimber3, D.N. Argyriou3, M.S. Torikachvili4

1

Ames Laboratory, USDOE and, Iowa State University, Ames, IA 50011

2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 3

Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Straße 100, 14109 Berlin, Germany 4

San Diego State University, San Diego, CA 92182

in CaFe2As2 [1]. The application of pressure can have significant 

effects on the enhancement or suppression of superconductivity. 

Particularly striking is the case of CaFe2As2 where the onset of

superconductivity was observed for pressures of only 0.2 GPa,

a very low value indeed. Our powder (BT-1) and single crystal

(BT-7) diffraction studies were carried out to detect any changes

in the structure that might be associated with the onset of 

superconductivity, and these investigations discovered dramatic 

changes in the structure and magnetism of CaFe2As2 under 

pressure.

It is important to first describe the different ways that one can

apply pressure to a sample for such experiments. The basic pressure 

cell arrangement consists of a sample immersed in a medium, 

such as a gas or liquid, and the force applied to that medium 

by a set of anvils is transmitted undiminished to the sample. In

the hydrostatic limit, the entire sample experiences the same 

pressure. However, depending on the properties of the medium

itself, nonhydrostatic effects can be realized. For example, at low

temperatures liquid media typically solidify and the hydrostatic 

limit cannot be realized. This is not an issue for He-gas pressure

cells for temperatures and pressures above the freezing line and,

so, they are capable of reaching the hydrostatic limit over a much

wider range of temperatures and pressures. The application

of hydrostatic pressure in these studies proved to be key in 

understanding the nature and behavior of CaFe2As2 under pressure.

Figure 2 shows BT-1 powder diffraction scans in a He-gas pressure 

cell through the nuclear (0 0 2) [panel (a)], (2 2 0)T [panel (b)],

and antiferromagnetic (1 2 1)OR [panel (c)] Bragg peaks (indices 

are either the tetragonal unit cell or the low temperature, ambient 

pressure orthorhombic unit cell) at selected temperatures and 

pressures [2]. At 50 K and ambient pressure (A), the splitting of 

the tetragonal (2 2 0)T into the (400)OR/(040)OR peaks, together

with the observation of the magnetic (1 2 1)OR magnetic peak 

(Fig. 2(c)), signals that the sample has transformed to the

orthorhombic phase (Fig. 2(b)). Then with increasing pressure,

dramatic changes take place in the measured diffraction patterns

between 0.24 GPa and 0.35 GPa. Above 0.35 GPa (Fig. 2(c)) 
NCNR 2009 Accomplishments and Opportunities 17

the magnetic peak is absent and the orthorhombic structure has 

transformed to a tetragonal phase, similar to the high-temperature 

ambient-pressure structure, but with extraordinarily different 

lattice parameters. This is most evident from the huge shift in the 

positions of the (0 0 2) and (2 2 0) peaks at (B) in Figs. 2(a) and 

2(b), respectively. We found an astonishing 9.5 % reduction in the 

c-lattice parameter with respect to the orthorhombic phase in this 

pressure-induced “collapsed” tetragonal (cT) phase, and a nearly 

5 % decrease in the unit-cell volume. There is a small increase 

in a, which produces an even more striking reduction of the c/a

ratio by nearly 11 %, a key parameter for bond geometries in the 

iron arsenides. With the pressure maintained at 0.63 GPa, an 

isostructural transition between the low temperature cT phase and 

the high temperature tetragonal structure was observed.

FIGURE 2: Scans through [(a) and (b)] nuclear and (c) magnetic peaks in 

neutron-diffraction pattern at selected temperatures and pressures. Note that 

the diffraction peaks change position dramatically due to the huge changes in 

the lattice parameters. In (c), the magnetic (1 2 1)OR magnetic diffraction peak 

for point A is clearly observed above the background taken at B. No new 

magnetic peaks for B and C were observed.

The dramatic structural transition to the cT phase was a surprise, 

but was then confirmed by spin-polarized total-energy calculations 

that revealed that the collapsed phase is indeed the most stable 

phase for the measured 5 % volume collapse [2]. Perhaps most 

intriguing was the prediction that the cT phase is nonmagnetic—

the iron moment is quenched. Indeed, no magnetic order or spin 

fluctuations have been observed in this phase.

Is the cT phase in CaFe2As2 then responsible for 

superconductivity? Here is where the story takes an interesting 

twist. The original resistivity measurements [1] on CaFe2As2

were taken in a conventional pressure cell using a liquid→solid 

pressure medium. It is worth noting here that CaFe2As2 is an 

extremely soft material, and because of the highly anisotropic 

nature of the change in the structure, the pressure realized in the 

collapsed phase was also highly anisotropic. When these resistivity 

measurements were repeated using a He-gas pressure cell, no trace 

of superconductivity for pressures below 0.7 GPa was found [3]. 

It appears that superconductivity only occurs in samples subject 

to a nonhydrostatic pressure component, perhaps due to phase 

separation, the appearance of some new as yet unidentified phase, 

or grain boundaries in a multiphase sample. 

FIGURE 3: Pressure-temperature phase diagram of CaFe2As2 under 

hydrostatic pressure determined from neutron and high-energy x-ray 

diffraction measurements. Filled and open circles (squares) denote phase 

boundaries determined upon heating and cooling at a set of pressures, 

respectively. Filled and open triangles denote phase boundaries determined 

upon decreasing and increasing pressure at a fixed temperature, respectively. 

The shaded area denotes the hysteretic region. The inset shows the change in 

lattice constants at the T-cT transition at 300 K.

To further elucidate the nature of the p-T phase diagram we 

turned to single crystal neutron diffraction measurements on 

BT-7 at NIST, along with high energy x-ray data at Sector 6 of 

the Advanced Photon Source, and on the E4 diffractometer at the 

Helmholtz-Zentrum Berlin für Materialien und Energie in Berlin 

[4]. The results of are summarized in Fig. 3,which clarifies the 

phase boundaries between the tetragonal, orthorhombic and cT

phases. Perhaps most interesting is the observation of an extremely 

broad range of phase coexistence at the pressure/temperatures of 

transitions between these phases. Under hydrostatic conditions 

sharp first-order transitions between the phases were observed. 

Subsequent clamp cell measurements revealed a very broad 

transition and coexistence region, confirming that there are 

important differences in behavior between hydrostatic and 

nonhydrostatic pressure. While these measurements have clarified 

the nature of the magnetic and crystal structures under pressure, 

the search for the superconducting phase fraction in CaFe2As2

under nonhydrostatic pressure conditions continues.

References

[1] M. S. Torikachvili, et al., Phys. Rev. Lett. 101, 057006 (2008).

[2] A. Kreyssig, et al., Phys. Rev. B 78, 184517 (2008).

[3] W. Yu, et al., Phys. Rev. B 79, 020511(R) (2009).

[4] A.I. Goldman, et al., Phys. Rev B 79, 024513 (2009).
18Condensed Matter

High-temperature superconductivity (high-Tc)discovered in 1986 remains one of the great unsolved 

problems of condensed matter physics. The phenomenon 

was first found in a class of Cu-O-based compounds

(cuprates). Although no explanation is yet completely

satisfactory, the current belief is that the magnetic moments 

of the Cu ions in some manner play a major role in the

superconductivity in cuprates. Thus the situation has stood,

until the recent discovery of an entirely new class of highTc superconductors featuring FeAs (iron pnictide) layers

that are analogous to the CuO planes, the major structural

feature in the cuprates.

The key question now becomes: what is the mechanism

of the superconductivity in these Fe-pnictide systems? 

The answer to this question is expected to shed light on 

the long-standing question of the mechanism of high-Tc

superconductors in general. Here, we present a brief review

of our first principles studies which clearly show that the Fespin is the key factor controlling many physical properties

of the pnictide systems, including atomic positions, crystal

cell size, structural phase transitions, and lattice vibrations, 

and which provide a strong clue about the superconducting 

mechanism. In particular, we show how giant magnetoelastic coupling (i.e., a large response of structure to a small 

change in the magnetization of its atoms) arises, and suggest 

that this enormous sensitivity of the structure to the Fespin may be a key ingredient in the mechanism of high-Tc

superconductivity in Fe-pnictides.

From accurate all-electron density functional calculations 

we showed [1] that there are strong and competing

magnetic interactions in these systems that explain both the

observed spin-pattern and the structural phase transition.

Our theory also predicted the sign of the lattice distortion 

which was later confirmed experimentally. Similarly, our 

prediction of very large magnetic exchange interactions (i.e.,

J1 and J2) [1] has recently been confirmed by measurements

of spin-waves up to 120 meV, which is almost the same

energy scale as spin-waves in the cuprates [2].

When the iron magnetism is ignored, the calculations

explain neither structure nor lattice vibration energies (i.e.,

phonons), resulting in large discrepancies between theory and

experiment.  In particular, as shown in Fig. 1, when the Fe-spin is 

turned off [3], the system basically collapses, resulting in a 12 % 

reduction in the distance between FeAs-layers for the case of

CaFe2As2. The response of the lattice to the change in magnetic

moment of its atoms is called magneto-elastic coupling and its 

magnitude is usually tiny, hardly measurable by x-ray or neutron 

scattering. However for the case of Fe-pnictide, this effect is 

enormous. To the best of our knowledge, such a giant coupling of

the lattice to its atom-spin state has not been seen before.  In our

recent study [3] we traced the origin of this c-axis collapse to the 

large As-As interaction between adjacent FeAs layers.

FIGURE 1: Total energy along a reaction path, showing that the CaFe2As2

tetragonal (T) phase goes directly to collapsed-tetragonal (cT) phase during 

structural optimization without Fe-magnetism. The insets show the initial 

(T-Phase) and final (cT-phase) CaFe2As2 structures with relevant bonddistances (in Å) and angles (in degrees). Note that in the cT-phase the change 

in the height of the FeAs layer and the change in the distance between FeAs 

layers are comparable, indicating a uniform compression of the whole lattice. 

In order to demonstrate that there is large hybridization between 

As ions in the CaFe2As2 system, we show the contour plots of the 

relevant orbitals in Fig. 2. It is very clear that the As ion below the 

top Fe-plane makes a bond (or hybridizes) with the arsenic ion 

which is above the lower Fe-plane. In the collapsed-phase the AsAs bonding along the c-axis gets significantly stronger. According

Key Role of Iron-magnetism in High-temperature 

Fe-pnictide Superconductors

T. Yildirim1

1

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899
NCNR 2009 Accomplishments and Opportunities 19

to bond-population analysis, the bond strength increases by a 

factor of two. Due to close proximity of the As ions in adjacent 

Fe-layers, the observation of the As-As interaction is probably not 

that surprising. What is surprising is to see that there is almost the 

same type of hybridization between two arsenic ions in the same

FeAs-layer as shown in the bottom panel of Fig. 2. The mechanism 

by which the c-axis shrinks is the strengthening of the bonding of 

the As ions above and below a given Fe plane as a consequence of 

the weakening Fe-As interaction with decreasing Fe-moment.

FIGURE 2: Contour plot of one of the orbitals that is responsible for the 

discovered As-As covalent bonding for the T-phase (top-left) and the cT-phase 

(top-right), respectively. Note that the As-As bonding present in both phases 

is much more significant in the cT-phase. The bottom panel shows another 

orbital on a slice along (110) plane, indicating clear hybridization between 

intra-layer As atoms below and above the Fe-plane in the T-phase.

So far we have shown that the inclusion of Fe-spin in calculations 

accounts for lattice parameters and internal atomic coordinates. 

Below we show that this inclusion also resolves most of the 

outstanding issues in the observed phonon modes in pnictides, as 

shown in Fig. 3. Our phonon calculations are done using the direct 

finite displacement technique, as described in Ref. [2]. The main 

advantage of this technique over standard linear response theory 

is that we treat the magnetism and phonon displacements equally 

and self-consistently. We have already seen that the Fe-magnetic 

moment is very sensitive to the As-z position and therefore it is 

not a good approximation to assume that the spins are fixed as the 

atoms move according to a given phonon mode. In our approach, 

this direct and strong interplay of magnetism and structure is 

treated self-consistently. 

As shown in Fig. 3, including the Fe-spin contribution to the 

atomic forces [2] allows us to accurately predict the positions 

of the measured peaks in the lattice vibrational density of states 

(DOS). Turning on the Fe-spin softens two particular phonon 

modes (namely, As-atoms vibrating along a line between planes, 

and in-plane Fe-Fe stretching modes), as observed experimentally, 

and therefore, through fluctuations of the Fe-spin state, these 

modes could have very large electron-phonon coupling. This large 

coupling may be related to the observed high-Tc. We are currently 

investigating this possibility.

FIGURE 3: Generalized Phonon DOS measured by inelastic neutron scattering 

at room temperature for BaFe2As2 (bottom black curve) [4] and the calculated 

GDOS with (middle blue) and without (top red) Fe-magnetism. Note that 

including the Fe-spin in the calculations softens the Fe-Fe in-plane and As 

c-phonons by about 10 % and 23 % and results a DOS that is in excellent 

agreement with the room temperature data (i.e., well above TN = 140 K).

In conclusion, we presented several examples which demonstrate 

that almost all of the observed structural and dynamical properties 

of Fe-pnictides can be explained in detail, provided that Femagnetism is always present in Fe-pnictide systems, even at 

temperatures well above TN. The iron magnetism could be in 

the form of fluctuating spin-density wave type small magnetic 

domains or it could be at the atomic limit of paramagnetic Fe 

ions. Further work is required to have a better understanding of 

the Fe-magnetism in these systems. From the results presented 

here it is clear that iron-magnetism in the Fe-pnictides is the key 

factor that controls atomic positions, lattice parameters, structural 

phase transition, phonon energies, and most probably the 

superconducting properties as well. 

References

[1] T. Yildirim, Phys. Rev. Lett. 101, 057010 (2008).

[2] T. Yildirim, Physica C (special issue on Fe-pnictides), 469, 425 

(2009).

[3] T. Yildirim, Phys. Rev. Lett. 102, 037003 (2009).

[4] M. Zbiri, et al., Phys. Rev. B 29, 064511 (2009).
20Biology

Cardiac myosin binding protein-C (cMyBP-C) is amodular protein that fine tunes the regulation of heart 

muscle contractions and is linked to the inherited heart

disease known as familial hypertrophic cardiomyopathy 

(FHC) [1]. Up to 1 in 500 adolescents and young adults are 

affected by FHC [2], which presents as a gradual thickening

of the ventricle walls of the heart and is a correlated with 

increased risk of heart failure. A large number of the 

gene mutations linked to clinical cases of FHC are in a

region that codes for the first four ‘regulatory’ modules of

cMyBP-C. There is increasing evidence that these modules 

affect their regulatory role through interactions with the 

thin filaments of heart muscle. We therefore undertook

to characterize the structure of these modules and of the 

assembly they form with actin in order to understand the 

molecular basis for cMyBP-Cs regulatory role. With this 

foundational knowledge, we can determine how FHClinked mutations disrupt that role and cause disease. 

Heart muscle is one of the ‘striated’ muscles, so called 

because of the stripes it reveals under the microscope arising

from inter-digitated thick and thin filaments, the primary

components of which are the proteins myosin and actin,

respectively. Muscle contraction and relaxation occurs as

the filaments slide past each other via the cyclic action of

cross bridges formed by the myosin heads

that extend from the thick filament to

bind to specific sites along the actin thin 

filament. These actomyosin interactions

generate the force required to drive the

sliding motion and are regulated by the

thin filament accessory proteins troponin 

and tropomyosin. In response to calcium 

binding to troponin, tropomyosin moves

to unveil the cross-bridge binding sites 

on the thin filament. Cardiac myosin

binding protein-C, first identified as a 

thick filament accessory protein, appears 

to provide an additional regulatory layer 

to the contractile cycle, with biochemical

and physiological data implicating the four

How Does Cardiac Myosin Binding Protein C Help to Maintain 

a Healthy Heart Beat?

A.E. Whitten1, C.M. Jeffries2, S.P. Harris3, J. Trewhella2

1

Bragg Institute , Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia 2

University of Sydney, Sydney, NSW 2006, Australia 

3

University of California at Davis, Davis, CA 95616

regulatory modules of cMyBP-C in modulating the myosin cross

bridge interactions; the modules are designated C0-C1-m-C2, or

C0C2).

Using small-angle x-ray scattering, we first demonstrated that

equimolar mixtures of C0C2 and actin form a large molecular

assembly. To determine the arrangement of actin and C0C2 within

this assembly we used small-angle neutron scattering with contrast

variation [1] (Fig. 1a). Differentiation of the C0C2 from the actin 

was achieved by using C0C2 that had been produced by bacterial

expression from cultures grown on D2O to yield a deuterated

protein (DC0C2). The DC0C2 has a different the neutron 

scattering-length density than the non-deuterated actin. The 

relative contributions to the total scattering (I(q)) of the DC0C2

and actin can therefore be modulated by systematic variation of

the solvent deuterium content. In solutions containing ≈ 40 % 

mole fraction D2O the scattering-length density of actin matches

that of the solvent and only DC0C2 contributes significantly to the

scattering, while DC0C2 is solvent matched between 90 % to

100 % D2O.

The scattering data revealed that the assembly had F-actin at its core,

with the DC0C2 decorating its exterior (Fig. 1b). As the length of 

the assembly was beyond the resolution of our data to determine, 

we analyzed the data initially in terms of the distribution of

scattering density in the cross-section. We had previously developed 

FIGURE 1: (a) Neutron contrast variation data on assemblies of DC0C2 with actin, solid lines 

are the fits of the model in Fig. 2 to the data. (b) Probable frequency distribution of distances 

between scattering centers in the cross-sectional area of the rod-like assembly. The profiles for 

the 40 % and 100 % data are dominated by the DC0C2 and actin components, respectively.

Comparison of the 100 % profile with that from pure F-actin shows the core is F-actin, while the 

DC0C2 extends to ≈ 200 Å, significantly beyond the ≈ 75 Å F-actin diameter.
NCNR 2009 Accomplishments and Opportunities 21

a structural model for the four-module C0C2 based on NMR 

structures and homology models for each module and small-angle 

x-ray scattering data for the intact C0C2 [2]. Using this model, 

and the fact that we were able to demonstrate that the assembly 

had approximate two-fold symmetry in its cross-section and thus 

decorated the F-actin in a regular manner, we were able to complete 

a comprehensive search of model space and determine a threedimensional structure of the assembly (Fig. 2, left) reveals C0C2 

bound at specific actin binding, decorating the fiber in a regular 

fashion. This structure fits all of the scattering data with nearly ideal 

fit parameters (Fig. 1a). 

Our model shows C0 and C1 interacting with the two 

neighboring actin molecules 

along the fiber (Fig. 2, 

middle), explaining the 

unexpected preservation 

of a filamentous C0C2-

actin assembly in solution 

conditions that normally 

support only monomeric 

actin. In muscle, the 

stoichiometry of cMyBP-C 

to actin is much lower than 

in this saturated assembly 

and so we confine further 

interpretation to the details 

of the C0C2-actin binding 

interface and implications 

this has for muscle regulatory 

mechanisms.

Our model suggests 

cMyBP-C can fine tune 

the regulation of heart muscle contractions via interactions with 

tropomyosin and/or myosin cross-bridges, thereby influencing the 

activation state of the thin filament (Fig. 2, right). Our structure 

predicts significant steric clashes with tropomyosin, especially 

under conditions of low Ca2+ when tropomyosin normally 

occupies a position that blocks myosin cross-bridge binding to 

the thin filament. If C0 and C1 displace tropomyosin away from 

this blocked configuration under relaxed (low Ca2+) conditions, 

then cMyBP-C could effectively prime thin filament activation by 

uncovering myosin binding sites in the absence of Ca2+. If C0 and 

C1 preferentially bind to activated thin filaments, then relaxation 

(following a decline in Ca2+) could be slowed. These observations 

suggest the molecular basis for observations in physiological data 

that suggest how C0C2 can ‘buffer’ the effects of Ca2+ in motility 

assays; facilitating some motility in the absence of Ca2+ and slowing 

motility in the presence of Ca2+. Intriguingly, the position of C0 

and C1 on actin is also predicted to overlap with myosin crossbridge, which could explain observations that cMyBP-C and 

myosin-S1 directly compete for actin binding. Our scattering 

experiments also demonstrate that the intact cMyBP-C must form 

a linkage between the thick and thin filaments of cardiac muscle 

providing a means by which the dynamics of the thick and thin 

filament spacings could be influenced during the contractile cycle 

which is important for healthy heart function.

Neutron contrast variation with deuterium labeling provides 

us with the means to extract structural data on the individual 

components in a protein assembly without bulky labeling or other 

less benign modification. As these assemblies are too lage for 

NMR analysis and typically resistant to crystallization, the ability 

to extract the level of detail obtained here provides an important 

pathway to critical evidence for determining the molecular 

mechanism underlying the function of this protein. Further work 

is underway to use neutron contrast variation to characterize 

the effects of phosphorylation and FHC-linked mutations on 

the interactions of cMyBP-C with actin and other heart muscle 

proteins in order to fully elucitdate its critical role in regulating a 

healthy heart beat. 

References

[1] A. E. Whitten, C. M. Jeffries, S. P. Harris, J. Trewhella, Proc. Natl 

Acad. Sci. U.S.A. 105, 18360 (2008).

[2] C. M. Jeffries, A. E. Whitten, S. P. Harris, J. Trewhella, J. Mol. 

Biol. 377, 1186 (2008).

FIGURE 2: Left Model structure of C0C2 (blue) decorated actin (red) filaments based on the neutron scattering data.

Middle Detailed view showing the C0 and C1 modules (blue) binding to neighbouring actin monomers (red and orange) 

in the filament. Right The actin filament (red) with a set of bound C0C2 molecules with the Ca2+ on (yellow) and off (white) 

positions of tropomyosin depicted. Note the strong steric clashes for the Ca2+ off tropomyosin position.
22Biology

Electrical signals in the nervous systempropagate between neurons along axons via

electric potentials that are generated by proteins

that reside within the cell membranes. Known 

as voltage-gated ion channels, these proteins

allow ions to pass through the cell membrane in a

controlled manner. In the voltage-gated potassium,

sodium, and calcium channels found in neurons

and muscle cells, a special part of the protein, 

called the voltage-sensing domain (VSD), moves 

inside the membrane in response to changes in the 

membrane potential and drives the ion conduction 

pore open or closed (gating) [1] (Fig. 1). Until

a few years ago, it was thought that VSDs were

unique to voltage-gated ion channels. This view

has changed radically with the discovery of new 

families of proteins that use VSD constructs for 

purposes other than ion channel gating [2]. There is

tremendous interest in the structure and function 

of such proteins. Researchers want to elucidate

the mechanism of ion gating in ion channels. 

Moreover, the portability of VSDs across the

genomes of different organisms can provide important clues

about evolutionary pathways.

Crystallographic studies using x-ray diffraction on voltagegated potassium channels have revealed the atomic structure 

of the VSD in crystallized channels and identified regions 

that move in response to changes in the membrane electric

field [3,4]. However, none of those studies were able to

demonstrate the structure and conformation of the voltagesensor domain in its native lipid environment. A picture of

the topology of the VSD in a lipid membrane was needed

in order to understand the role of the lipid in the protein 

stability and function, and ultimately, in the voltage-gating

mechanism. We have developed an approach that employs 

neutron diffraction to obtain the image of functional

voltage sensor domains in lipid membranes. 

We focused our efforts on the voltage-sensing domain of

KvAP, an archaebacterial channel from Aeropyrum pernix [5],

because this domain can be robustly expressed, stably purified, 

and reconstituted into lipid membranes. The voltage-sensing 

domains were expressed in E. coli, purified, and transferred to 

lipid vesicles (reconstitution of the VSDs into proteoliposomes). 

Lipid multilayer samples were prepared by deposition of aqueous

dispersions of proteoliposomes on cover glass slides. They were 

allowed to dry and rehydrated from water phase at 93 % relative 

humidity throughout the diffraction experiments. Samples 

containing a few thousands lipid bilayers with incorporated VSDs

were measured and strong lamellar diffraction patterns were

observed (Fig. 2) and used to generate one dimensional, absolutescale, scattering-length density profiles normal to the plane of the

lipid bilayer. We have determined the protein distribution using

contrast variation between protonated and deuterated VSDs. The 

voltage-sensing domain of KvAP was uniformly deuterated to 74 %

1

University of California, Irvine, Irvine, CA 92697 2

National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892 3

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 4

University of California, Irvine, Irvine, CA 92697 5

University of Missouri, Columbia MO 65211 6

National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892

How Do Lipid Membranes Accommodate Voltage-sensing Domains of 

Ion Channels?

M. Mihailescu1, D. Krepkiy2, J.A. Freites1,4, E. Schow4, D.L. Worcester 5,1,3, K. Gawrisch6, D. Tobias4,

S.H. White1 and K.J. Swartz2

FIGURE 1: Top view (from above the surface of a lipid membrane) of a voltage-gated 

potassium channel.
NCNR 2009 Accomplishments and Opportunities 23

and multilayers were formed with either protonated or deuterated 

protein at the same protein:lipid ratio and lipid composition. 

Fourier transformation of the diffraction data to obtain scattering 

length density profiles and subtraction of the individual profiles 

for the labeled and unlabeled protein reveals the distribution of the 

protein across the bilayer (Fig. 3a; red). 

FIGURE 2: Neutron diffraction data collected at the AND/R (NCNR) for lipid 

multilayers samples with incorporated VSDs: Data displayed are for neat lipid 

(black), unlabeled VSD in lipid (blue) and deuterated VSD in lipid (red). The 

inset is a schematic illustration of the experimental setup.

The profile is presented with its uncertainty band derived from 

the standard deviation of the measured data. Maxima in the 

density distribution are observed in the headgroup region of the 

bilayer and minima in the inter-bilayer space. These findings firmly 

establish that voltage-sensing domains adopt a transmembrane 

topology, with the four helices oriented roughly normal to the 

membrane plane. Moreover, the protein distribution (Fig. 3a; 

red) exhibits extensive overlap with the water distribution (Fig. 3a; 

blue) within the confines of the lipid membrane, suggesting that 

the voltage-sensing domains are highly hydrated within the bilayer. 

Because neutron diffraction reflects an average distribution of 

atoms, atomic details in the bilayer structure close to the VSD 

are not easily revealed in the experiment. To explore details in 

the protein, lipid and water distribution we employed molecular 

dynamics simulation for VSDs embedded in lipid bilayers. The 

simulation results (Fig. 3b) are in qualitative agreement with the 

experiment regarding the trans-membrane disposition of the 

four helical segments of the VSD and the overlap with the water 

distribution. Additionally, the simulations predict that about 4 % 

all water in the system is intimately associated with the VSDs, and 

that the lipid layers in contact with the protein are perturbed to a 

much greater extent than lipids several layers away from the protein 

(Fig. 3b). 

Our results provide direct evidence that voltage sensors domain 

topology in a membrane environment and will be relevant for 

other important classes of membrane proteins. They show that the 

voltage-sensing domains of voltage-gated ion channels interact 

profoundly with the surrounding membrane and water, in a 

manner that facilitates their movement and function within the 

lipid membrane. 

References

[1] K. J. Swartz, Nature 456, 891 (2008).

[2] Murata Y. et al., Nature 435, 1239 (2005).

[3] Y. Jiang, et al., Nature 423, 33 (2003).

[4] S. B. Long, et al., Nature 450, 376 (2007).

[5] V. Ruta, et al., Nature 422, 180 (2003).

FIGURE 3: Distribution of the 

protein in lipid membranes:

(a) Neutron diffraction results. 

Trans-bilayer distribution of 

the protein (red), water (blue) 

and lipid bilayer (black). (b)

Molecular dynamics simulation 

results. Snapshot of the region in 

the vicinity of a voltage-sensing 

domains. Waters within 6 Å of 

protein are shown as red/white 

spheres while all other waters are 

colored purple. Phosphocholine 

headgroups are colored yellow 

and the acyl chains are colored 

light green.
24Biology

Can fluid shear in the flow of blood alter the structure of

blood proteins? The question is relevant to medicine

and hematology as well as biophysics. Many biochemical 

studies suggest that the function of the largest protein in 

blood, Von Willebrand Factor (VWF), is regulated by fluid 

or hydrodynamic shear. Using a combination of small angle 

neutron scattering (SANS) and fluorescence spectroscopy, 

we studied if, when and how fluid shear promotes changes

in the conformation of this blood protein [1], and here we

highlight our results.

VWF occurs in circulating blood at concentrations of 

10 μg/mL to 20 μg/mL. It exists both as a dimer with

molecular weight of 500 kDa and as a linear multimer with 

molecular weight ranging from 1 MDa to 20 MDa (Fig. 1).

Previously, using SANS, we showed that this protein

resembles a loosely packed ellipsoidal molecule in which 

intra-molecular interactions within the protein stabilize

its solution structure [2]. By acting as a bridge/adaptor 

molecule that aids the binding of platelets to sites where

the inner lining of the blood vessel has been injured, VWF

plays a critical role in regulating platelet clot formation in 

narrowed arteries. The binding of VWF to human blood

platelets is necessary to stop bleeding but it also contributes

to blood-clotting events in arteries that lead to heart attacks 

and strokes.

Many of the functions of VWF are regulated by fluid shear.

Among these, it is known that VWF supports platelet

adhesion only above a minimum/ threshold shear rate. 

Lower shear rates do not efficiently support efficient platelet 

tethering and rolling interactions. A blood protease called 

ADAMTS-13 cleaves VWF in solution, and in normal human

physiology this cleavage only takes place in the presence of fluid

shear [3]. Cleavage of VWF by ADAMTS-13 dynamically 

regulates protein multimer distribution in circulation.

Additionally, fluid shear regulates VWF size dynamically by the 

process of protein self-association [4]. 

For the current study, we purified VWF from blood plasma 

cryoprecipitate obtained from human donors. Shear was applied

to this purified protein using a quartz Couette cell [5]. Protein

conformation was measured in real-time using SANS at the 30 m 

NG-3 instrument. The length scales studied varied from 2 nm 

to 140 nm and the maximum applied shear rate was 3000 s-1

(Fig. 2A). These SANS experiments show prominent changes in 

VWF scattering at length scales < 10 nm (scattering vector, q,

range > 0.6 nm-1) (Fig. 2B). The control protein, Bovine Serum

Albumin (BSA), does not display such alteration in scattering

upon shear application.

Computer modeling was performed with the goal of suggesting 

potential mechanisms that can account for the observed

changes in VWF scattering at high q upon shear application.

Both the protomer/dimer VWF, and the multimeric VWF

were simulated. Since the length scales where structural 

changes are more prominent occur at < 10 nm, we focused on

simulations that change the arrangement of individual VWF 

domains located within the globular head section of the protein

(Fig. 2C). The semi-quantitative agreement of these simulation

Control of Protein Structure and Function by Hydrodynamic Shear

S. Neelamegham1, I. Singh1, E. Themistou1, L. Porcar2

1

State University of New York, Buffalo, NY 14260 2

NIST Center for Neutron Research, National Institutes of Standards and Technology, Gaithersburg, MD 20899

FIGURE 1: VWF structure: Schematic of linear multimeric VWF protein based on electron microscopy studies. A dimer unit with molecular 

weight of 500 kDa is shown in the dashed box.
NCNR 2009 Accomplishments and Opportunities 25

results (Fig. 2D) with experimental data (Fig. 2B) suggest that 

structural changes in the VWF globular head section may occur at 

small length scales upon application of low shear rates < 3000 s-1.

FIGURE 2: VWF subjected to fluid shear: A. Setup for shear-SANS 

experiments. 0.6 nm neutrons are scattered by a protein sample placed in 

a Couette cell. Area detectors placed at either 1.95 m or 10.05 m detect 

scattered neutrons. B. I(q) versus q plot for a representative experiment. 

Scattering intensity prior to shear is shown by empty green circles and during 

shear (3000 s-1) by filled red circles. The inset shows the applied shear profile. 

Changes in scattering intensity suggest that structural changes in VWF occur 

at q* > 0.6 (corresponding to a length scale < 10 nm). C. Potential scattering 

profile changes due to protomer VWF was modeled. Here, we examined 

the effect of changing the arrangement of domains in the globular-section of 

VWF. D. Alterations in domain level features result in a decrease in scattering 

intensity slope in the VWF protomer at high q ( > 0.6 nm-1, green to red). 

Changes in scattering intensity in this panel of simulated results qualitatively 

resemble the experimental data in panel B.

In order to extend the shear rate from physiological flow 

(< 3000 s-1 to 5000 s-1) to shear rates that can occur during 

pathological flow ( > 5000 s-1), we examined alternative strategies 

to quantify protein structure changes. In these investigations, 

VWF was sheared in a cone and plate viscometer at shear rates up 

to 9600 s-1, and protein structure was assayed by measuring the 

binding of a fluorescent probe: 4,4’-Bis (1-anilinonaphthalene 

8-sulfonate) (bis-ANS) to hydrophobic pockets exposed in the 

sheared protein. As seen in Fig. 3, while bis-ANS exhibits low 

fluorescence signal in solution, the binding of this dye to VWF 

both increased fluorescence and caused a shift in peak emission 

wavelength to lower values. Application of shear at shear rates 

> 2300 s-1 further augmented the binding of bis-ANS to VWF. The 

measured absolute fluorescence signal was ≈ 110 % and ≈ 220 % 

higher than no-shear control at 6000 s-1 and 9600 s-1, respectively. 

FIGURE 3: Fluorescence spectroscopy using bis-ANS: Representative spectra 

for experiments performed with 60 μg/mL VWF. Bis-ANS binding to VWF 

increases absolute fluorescence by 5-fold to 10-fold over HEPES buffer signal 

(squares). Application of shear for 5 min at 6000 s-1 or 9600 s-1 further 

increased absolute bis-ANS signal by 110 % to 220 % compared to no-shear 

control (0 s-1).

Overall, SANS studies suggest that VWF may undergo 

conformation change under physiological flow conditions. 

These changes occur at small length scales. Studies with bis-ANS 

demonstrate marked increase in bis-ANS binding at shear rates 

> 2300 s-1. Together, the data suggest that local rearrangements 

at the domain level may precede changes at larger length scales 

that accompany exposure of protein hydrophobic pockets. It is 

likely that changes in VWF conformation described here regulate 

protein function in blood circulation.

References

[1] I. Singh, E. Themistou, L. Porcar, S. Neelamegham, Biophys J. 96,

2313 (2009).

[2] I. Singh, H. Shankaran, M.E. Beauharnois, Z. Xiao, Alexandridis 

P, Neelamegham S., J Biol Chem. 281, 38266 (2006).

[3] H. M. Tsai, I. I. Sussman, R. L. Nagel, Blood 83, 2171 (1994).

[4] H. Shankaran, P. Alexandridis, S. Neelamegham, Blood. 101,

2637 (2003).

[5] L. Porcar, W.A. Hamilton, P.D. Butler. Review of Scientific 

Instruments 73, 2345 (2002).
26Engineering

Neutron Measurements of Preferred Orientation and the Prediction of 

Forming Properties in Automotive Sheet Materials

T. Gnäupel-Herold1, T. Foecke2, A. Creuziger2, M. Iadicola2

Asubstantial part of manufacturing is involved withsheet metal forming for producing panels, covers, or 

automotive bodies. Currently, the automotive industry is

experiencing a shift to light weight, high strength materials

to promote fuel economy. Both trends—thinner, higher 

strength steels and lighter, Al or Mg-based alloys—bring 

about enormous problems related to the accurate prediction 

of forming properties such as springback, forming limits and 

surface quality. It is now widely recognized that polycrystal

plasticity modeling together with better materials property 

data for forming-like conditions can improve the accuracy

of overall modeling with the goal to predict the stress-strain 

state at any given location in the formed part. These efforts are 

illustrated in this work.

The underlying microscopic process of sheet metal forming

is the plastic deformation of constituent grains. For a

single grain, this process takes place as a slip on certain

crystallographic planes in specific crystal directions, thus 

leading to a change in the orientation and the shape of the

grain. A sheet as a whole consists of many grains in different 

orientations which, due to their mutual interactions and 

depending on the applied stresses, develop distinctive

distributions of grain orientations (texture). However, texture

is not only an effect of deformation, it is also a crucial property

setting limits for further deformation (hence the necessity for

a “good” starting texture in the sheet before forming). This 

view of texture is currently seeing a new level of complexity

from the introduction of TRIP steels (TRansformation

Induced Plasticity), a relatively new class of advanced high

strength steels that show both high strength and high ductility

due to the stabilization of the austenite phase and straininduced deformation from the retained austenite into the 

martensite phase. Thus, the challenge for modeling this three 

phase system is to elucidate not only the texture evolution of

each phase but also the shifting phase content. The texture 

response for three basic deformation modes in TRIP590 is

shown in Fig. 1 for the principal directions of the initial sheet

RD (rolling direction) and TD (transverse to RD).

FIGURE 1: Uniaxial stress-strain curve of TRIP 590 (in RD and in TD) together 

with pole figures for the (200) planes of ferrite (majority phase, bcc structure) 

and austenite (minority phase, fcc structure) for the three different deformation 

modes: uniaxial tension (U) in RD, plane strain in the rolling direction (PS, 

no shrinking in TD) and balanced biaxial (equal strain in RD and TD). The 

meaning of each mode is shown on the bottom, left indicating the shape 

change of a circle mark on the sample surface.

It is remarkable that for austenite the texture change is rather 

subtle which means that this phase participates in the deformation

not just through slip and grain rotation but increasingly through

transformation to martensite. The consequence is that the texture 

exhibits strengthening but no change in the main components.

Ferrite is the majority phase and it has no such transformation

available. However, the ferrite grains are surrounded to an

increasing extent by the ‘hard’ martensite phase, thus leading to a

composite-like strengthening in ferrite where the martensite grains

act as obstacles for dislocations. The martensite phase in TRIP

590 is difficult to observe because of the complete overlap with 

ferrite peaks but its content can be determined indirectly through

the retained austenite fraction. The determination of the retained

austenite content receives a new treatment here. A commonly

practiced method is the comparison of a large number of ferrite/

austenite reflections. Only limited orientation averaging is applied

to individual reflections; the texture effect is dealt with through

the number of different reflections (hkl). The approach used here

is based on the premise that the pole figure data for ferrite (overlap

1

University of Maryland, Department of Materials Science and Engineering, College Park, MD 20742, and

 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899-6102 2

Metallurgy Division, National Institute of Standards and Technology, Gaithersburg MD 20899-8553
NCNR 2009 Accomplishments and Opportunities 27

with the martensite phase) and austenite allow the integration of 

the diffracted intensities over all orientations, thus removing the 

texture effect completely. The comparison with the theoretical 

intensities allows the calculation of the volume fractions (Fig. 2). 

It is noteworthy that the austenite volume fractions decrease to 

very low levels (< 1 % for BB) for which both the texture and the 

volume fraction could still be reliably determined.

FIGURE 2: Retained austenite content for TRIP 590 in uniaxial tension (RD, 

TD), plane strain (PS-RD, PS-TD) and balanced biaxial (BB). The errors were 

estimated from repeated measurements on undeformed samples.

The transformation from austenite to martensite is a well known 

and studied transformation. Using the lattice parameters of austenite 

and martensite, it is possible to predict not only the planes on which 

the transformation will occur, but also the driving energy of the 

transformation, referred to as a transformation potential. Using 

the crystallographic theory of martensite (CTM), transformation 

potentials were calculated as a function of texture (orientation of 

austenite grains) and the applied stress state (Fig. 3). 

The transformation potential calculation predicts that both 

the uniaxial and plane strain RD samples will have higher 

transformation potential values than the uniaxial and plane strain 

TD samples for orientations found in the measured pole figures. 

The balanced biaxial samples have a uniformly high transformation 

potential, but the values are lower than the peak plane strain RD 

values. From these data, the balanced biaxial loading condition 

(BB) should cause the most transformation, followed by plane 

strain RD and uniaxial RD, plane strain TD and uniaxial 

TD. High transformation potentials indicate a higher rate of 

transformation austenite to martensite, thus resulting in a lower 

volume fraction as confirmed by the experimentally determined 

retained austenite in Fig. 2.

The effects of texture, orientation and stress state on the austenite 

to martensite phase transformation in TRIP steel were investigated 

in this work. The crystallographic texture was determined for 

ferrite and austenite in various deformation modes, and the 

retained austenite fractions were obtained down to levels < 1 %. 

The austenite-martensite transformation was simulated using the 

crystallographic theory of martensite. This allowed the prediction 

of transformation potentials for different stress states/deformation 

modes. From these data, the texture components that are typical 

in as-processed TRIP steels were found to correspond to low 

values of the transformation potential. Grains aligned with these 

orientations would require higher stresses to transform than other 

orientations, thus leaving the austenite texture relatively stable 

but with increased intensity by the transformation of grains in 

orientations with high transformation potential.

References

[1] A. Creuziger, T. Foecke, submitted to Acta. Mater.

FIGURE 3: Transformation 

potential in a section of Euler 

space for the stresses indicated in 

the bottom, right for combinations 

of stress directions and sign 

(+/-). A point in these graphs 

corresponds to a specific austenite 

grain orientation. Key to notation: 

Uniaxial tension in RD (RDT), plane strain in RD (RD-PS), 

balanced biaxial tension (BB), 

plane strain along TD (TD-PS), 

uniaxial tension along TD (TD-T), 

deep drawing in TD (TD-DD), pure 

shear along +TD (TD-S), extrusion 

in RD (RD-EX), compression in 

RD (RD-C), balanced biaxial 

compression (BB-C), compression 

in TDs (TD-C), extrusion along TD 

(TD-EX), pure shear in +RD (RD-S), 

deep drawing in RD (RD-DD).
Chemical Physics

28

Water is often found confined in nanoscopic pores oron both hydrophilic and hydrophobic surfaces. For

example, in proteins water is exposed to both hydrophilic

and hydrophobic moieties. In order to better understand

how the behavior of water is affected near a hydrophobic

surface, we have investigated the dynamics of water confined

in a hydrophobically modified nanoporous silica matrix,

MCM-41-SM1-18 [1]. MCM-41-SM1-18 is a chemically

treated form of hydrophilic-nanopored MCM-41-S to make

the pore surfaces partially (42 %) hydrophobic [1]. In so 

doing the pore size is reduced from 18 Å to ≈ 15 Å. Using

a confinement matrix with ≈ 15 Å pore dimension, it was

possible to avoid the crystallization of water even below the 

homogeneous nucleation temperature TH ≈ 235 K, allowing

measurements over a temperature range from 300 K to 

210 K. This is relevant because it is believed that the

anomalous behavior of water, such as the density maximum

at 277 K or the tendency of the thermal expansion

coefficient, the isobaric specific heat, and the isothermal

compressibility to diverge at a temperature somewhat below

TH, can be understood only by probing water in deeply 

supercooled states.

The neutron scattering cross section of hydrogen atoms 

is much larger than silicon or oxygen. Hence, neutron

spectroscopy is useful in studying the dynamics of water

confined in silica matrices. Since incoherent scattering of

neutrons from hydrogen is much stronger than coherent

scattering, experiments on hydrogenated samples give 

information on the single particle dynamics of the hydrogen 

atoms in the system, simplifying the modeling of the data. 

Moreover, neutron scattering provides information on 

the geometry of the investigated motion at the nanometer 

scale. Thus, measuring the broadening of the elastic line

(quasielastic neutron scattering: QENS) arising from

the relaxation dynamics of the system yields both spatial 

and temporal information on the diffusive motion of the 

H atoms. To follow the slowing down of water confined

in MCM-41-SM1-18 in the temperature range from

300 K to 210 K, we have collected data on three NCNR 

spectrometers, namely the Disk Chopper Spectrometer (DCS), the

High Flux Backscattering Spectrometer (HFBS), and the Neutron

Spin Echo (NSE) spectrometer. Together these instruments cover a 

dynamic range from picoseconds to nanoseconds over length scales

from fractions of an Angstrom to several Angstroms.

FIGURE 1: a) Values of the intermediate scattering function measured by 

NSE plotted semilogarithmically as a function of follow straight lines 

whose slope depends only on temperature. b) Scaling plot of the susceptibility 

obtained from the DCS data. By plotting χ”/ χ”p as a function of ω/Q2 all the 

curves at the same temperature collapse onto the same master curve, which 

in the limit of high ω/Q2 lies parallel to the straight black line with slope -0.5, 

confirming that, as found by NSE, β = 0.5 and Γ ~Q2.

The data collected on the three spectrometers show that the self

Intermediate Scattering Function (ISF) of the hydrogen atoms in 

the system can be described by a stretched exponential function,

I(Q,t)=exp{-[Γt]β}. Over the range of investigated momentum

transfers, Q, (from ≈ 0.2 Å-1 to ≈ 1 Å-1, where the ISF reflects

Water Dynamics in Hydrophobic Confinement

A. Faraone1, K.-H. Liu and C.-Y. Mou2, and Y. Zhang and S.-H. Chen3

1

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 

and University of Maryland, College Park, Maryland 20742 2

National Taiwan University, Taipei 106, Taiwan 3

Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
NCNR 2009 Accomplishments and Opportunities 29

mostly the water center of mass translational dynamics), the 

stretching exponent β = 0.5. The Q dependence of the relaxation 

rate (Γ ) is quadratic as can be seen in a semilog plot of I(Q,t) versus 

Q t

2 , as measured using NSE (Fig. 1a), as well as by a log-log 

plot of the susceptibility, χ" = ωSself

H (Q, ω), obtained from the DCS 

data versus ω/Q2

 (Fig. 1b). This finding clearly indicates that the 

heterogeneous scenario applies: the system displays a distribution 

of relaxation times, probably related to the different microscopic 

environments experienced by the water molecules. The diffusive 

behavior of the individual molecules is retained, with an average 

diffusion coefficient, D = /(2Q2

). In Fig. 2 the values obtained 

for 〈D〉 are shown together with the results measured for bulk 

water by NMR (red curve). Remarkable agreement is found in the 

results from the three spectrometers. At high temperature the 〈D〉

values of water confined in MCM-41-SM1-18 tend to be similar 

to those reported for bulk water. However, it seems plausible that 

at temperatures (T > 300 K), higher than those investigated in 

this work, the dynamics of bulk water is slightly slower than that 

of water confined in the hydrophobically modified matrix. On 

the other hand, in the deeply supercooled region, the diffusion 

coefficient of bulk water tends to decrease with the lowering of 

the temperature much faster than water confined in MCM-41-

SM1-18. This is not surprising because it is well known that, in 

bulk water, the inverse of D seems to diverge at T ≈ 228 K. Such a 

singularity might be due to the effect of the second critical point 

of water [2] or to the effect of the hydrogen bond network [3]. 

While, the divergence is not directly observable in bulk water, we 

found that the singularity is avoided by the dynamic crossover 

of water in confined systems [4]. Overall, in the investigated 

temperature range, the geometric confinement slows down the 

dynamics of water as compared to the bulk.

FIGURE 2: a) the temperature dependence of <D> in hydrophobic MCM41-SM1-18. The continuous red line represents the values obtained for bulk 

water. The dashed black line is the fit to the data with a VFT law. Inset b) 

compares the average characteristic translational relaxation times of water in 

MCM-41-SM1-18 with that of water in hydrophilic MCM-41-S-14.

The 〈D〉 data have been fitted using a Vogel-Fulcher-Tammann 

(VFT) law, which is commonly used to analyze the temperature 

dependence of the transport coefficients in fragile glass forming 

fluids: 〈D〉=D0 exp[-DfT0/(T-T0)]. D0 is the diffusion coefficient 

in the infinite temperature limit. We obtain that the fragility 

parameter, Df

, is 13.8 ± 0.3, whereas the temperature of the ideal 

glass transition, T0, is (121 ± 1) K. Df

 in this case is higher than 

that reported for water in hydrophilic MCM-41-S with similar 

pore size [4], indicating that water in hydrophobic confinement 

behaves as a stronger glass-former. The result obtained for T0 is 

not very different from the commonly accepted value of the glass 

transition temperature of water, 135 K. 

The inset b) of Fig. 2 shows the average characteristic relaxation 

time 〈τ0〉 for water confined in a hydrophilic MCM-41-S sample 

with a pore diameter of ≈ 14 Å, compared to that in MCM41-SM1-18. The comparison of the dynamics of water in these 

two similar confining media, differing only by the hydrophilic 

or hydrophobic characters of their walls, highlights the effect of 

the interaction with the confining surface in contrast to purely 

geometric effects. At high temperature both samples have the 

same relaxation time. Around room temperature, therefore, the 

water molecules have enough kinetic energy to overcome the 

interaction with the confining wall. In the deeply supercooled 

region, like supercooled bulk water, H2O molecules confined in 

hydrophilic sieves show a much stronger dependence of relaxation 

time on temperature. This finding suggests that water confined 

in a hydrophilic matrix is qualitatively more similar to bulk water 

than to water confined by hydrophobic walls. This finding can 

be related to a more extensive disruption of the hydrogen bond 

network formation in the hydrophobic confinement. The dynamic 

crossover, from a non-Arrhenius to an Arrhenius behavior, was 

not observed in this work. This could be due to the fact that 

hydrophobic confinement lowers the crossover temperature, as in 

the case of DWNT [5].

References

[1] A. Faraone, K.-H. Liu, C.-Y. Mou, Y. Zhang, and S.-H. Chen, J. 

Chem. Phys., 130, 134512 (2009).

[2] P.H. Poole, F. Sciortino, U. Essmann, and H.E. Stanley, Nature, 

360, 324 (1992).

[3] R.J. Speedy and C.A. Angell, J. Chem. Phys., 65, 851 (1976).

[4] A. Faraone, L. Liu, C.-Y. Mou, C.-W. Yen, and S.-H Chen, J. 

Chem. Phys., 121, 10843 (2004).

[5] X.-C. Chu, A.I. Kolesnikov, A.P. Moravsky, V. Garcia-Sakai, and 

S.-H. Chen, Phys. Rev. E, 76, 021505 (2007).
Chemical Physics

30

Understanding how hydrogen interacts with high surface area materials, particularly those that are 

strong absorbers, is a requirement for the rational design 

and subsequent synthesis of new materials that could one 

day be used to safely store large amounts hydrogen. The 

long-term view is that this combination could be a potential 

replacement for the gasoline engine when coupled with 

fuel cells to power the automotive drive train using electric 

motors. While there are promising mechanisms for storing 

large amounts of hydrogen in solid materials that take up 

much less space than the equivalent amount of gas, there 

remain several roadblocks to practical use. When stored on 

high surface area materials, hydrogen is weakly bound and 

generally requires low temperatures to achieve significant 

storage capacities. To be able to increase the storage capacity 

at room temperature it has been suggested that increasing 

the interaction energy of hydrogen with the surface to (15 

to 25) kJmol-1 would be necessary [1] and that one potential 

mechanism could be to use favorable interactions of 

hydrogen with metal ions. The combined work shown here 

indicates that the interaction with the metal center can be 

well understood and quantified with a general set of trends 

that depend on simple physical characteristics of the metal 

embedded in the metal-organic framework (MOF). 

The ability to control the H2 binding energy that governs 

the adsorption in materials ranging from microporous solids 

to metal hydrides is key to making hydrogen storage a reality 

for vehicular use and as such is the focus of much research. 

In this regard, MOFs, comprised of metal ions linked via 

organic ligands into porous three-dimensional solids can 

provide the flexibility of being able to control not only the 

surface area and pore geometry but also the accessibility of 

gas to interact with the coordinated metal ions.

Our previous research has shown that hydrogen binds 

directly to the unsaturated metal coordination sites within 

certain classes of MOF materials. Along with exhibiting 

amongst the highest observed enthalpies [2] of hydrogen 

adsorption known in physisorption systems, there is 

an overall increase in the areal density of the adsorbed 

hydrogen on the surface [3] that is a direct consequence of the 

attraction of hydrogen to these Coordinately Unsaturated Metal 

Centers (CUMC). Despite the significant progress, there is still 

uncertainly as to how the metal is binding the hydrogen and giving 

rise to the increased enthalpy, and what is the best choice of metal 

to optimize this binding.

FIGURE 1: The local coordination environment of adsorbed hydrogen with 

different metal centers in MOFs as determined from neutron powder diffraction. (a) D2 binding close to the Cu2+ metal in the HKUST-1 paddlewheel, (b) 

and D2 adsorbed in the pore of Zn-MOF-74 with a close-up view (bottom left). 

Thermal ellipsoids for the deuterium molecule are green, carbon atoms are 

gray, oxygen atoms red, and hydrogen on the ligands are pink.

The porous structure of HKUST-1 has several different sized 

cavities that are available to the adsorbed gases, but the primary 

77 K adsorption site for H2 is at the M2+ cation. Figure 1a shows 

the local paddlewheel coordination environment around the 

copper ions with available coordination sites along the Cu-Cu 

axis. For the 1-dimensional pores of MOF-74 the metal cations 

are bonded to five oxygen atoms in a square-pyramid coordination 

environment, leaving the cation in the center of the square plane 

open and accessible to the adsorbed gas molecule (Fig. 1b). For ZnMOF-74 gas adsorption studies indicate a rather large hydrogen 

enthalpy of adsorption of -8.8 kJ/mol, and a relatively large excess 

hydrogen uptake capacity of 2.8 % mass fraction for the modest 

surface area of 870 m2/g. In contrast the adsorption in HKUST-1 

is typically characterized by an enthalpy of adsorption of -6 kJ/mol, 

and a relatively large excess hydrogen uptake capacity of ≈ 4 %.

To experimentally clarify exactly how it is the di-hydrogen binds 

to the copper center we used inelastic neutron scattering to probe 

the quantum transitions of the associated H2. Detailed rotational 

spectra as a function of increasing H2 loading were taken using the 

FANS spectrometer and the characteristic spectrum of hydrogen 

Toward an Improved Understanding of Hydrogen 

Interactions with Coordinated Metals

C.M. Brown1, W. Zhou1,2, Y. Liu1,2, H. Wu1,2, T. Yildirim1, V.K. Peterson3, C. Kepert4

1

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899

2

Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742

3

The Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai, N.S.W. 2234, Australia.

4

School of Chemistry, The University of Sydney, N.S.W. 2006, Australia
NCNR 2009 Accomplishments and Opportunities 31

transitions from the lowest rotational ground state when adsorbed 

in HKUST-1 are shown in Fig. 2(a). To obtain the momentum 

transfer (q) dependence of the lowest energy transition and 

confirm its rotational nature, we used the DCS spectrometer and 

fit the resulting intensities to the model for a free rotor (Fig. 2b). 

While the model includes a variable for the H-H bond distance, 

we found it unnecessary to vary this from the ideal value of 0.74 Å, 

and extracted a small mean-squared displacement of 0.175(1) Å2

for H2 at the Cu2+-site compared to ≈ 0.3 Å2 at the weaker ligandassociated sites. 

FIGURE 2: (a) Inelastic neutron scattering data for the H2 adsorbed only at the 

Cu2+ site in HKUST-1. Assignments of rotation (Rot) or translation (Trans) are 

made based both on experiment and with the aid of calculations. Inset: The 

local coordination for a classical DFT calculation as a function of the hydrogen 

rotation results in the orientational potential (perpendicular to the Cu-Cu axis 

(blue) is favorable; parallel orientation (red) is 78 meV less so). Solving for 

the rotational levels indicates that the transitions to the split first-level should 

appear around 9.6 meV and 37 meV. Calculated phonon energies x ́ = 9.56 

meV, y ́ = 13.44 meV, and z ́ = 22.87 meV. (b) The assignment to a quantum 

rotational transition of the ≈ 9.5 meV peak is determined from a separate 

measurement of the momentum transfer dependent intensity using the DCS 

spectrometer.

First-principles calculations were performed on the 3-D crystal 

as a function of the hydrogen orientation with respect to the 

Cu-dimer axis (Fig. 2a, inset, which shows an H2 and a portion 

of the paddlewheel). The resulting potential is shown as a globe 

in the figure and is dominated by a Coulombic interaction where 

the di-hydrogen prefers to lay flat against the CUMC (by ≈ 78 

meV) and experiences almost negligible electron transfer. Further 

analysis predicts the rotational and translational frequencies that 

allow us to completely assign the vibrational spectrum [4] in 

Fig. 2(a). 

Since we are able to understand the interactions of H2 with a 

specific CUMC, it is of interest to observe how these properties 

trend across an isostructural series of differing transition metal 

ions and compare this to experimental properties related to their 

hydrogen storage capacities [5]. The existing MOF-74 series 

was useful for this purpose, though we were also successful in 

extending this family of compounds making observed trends 

more apparent. Coupling the physical measurements to specific 

elemental characteristics required ab initio calculations. Select 

parameters that exhibit strong correlations are detailed in Fig. 3. 

Of particular note is how the calculated total binding energy 

for the MOF-74-D2 system varies in parallel to the experimental 

isosteric heat of adsorption. The isosteric heat is also anticorrelated with how close the H2 molecule is calculated to 

approach the CUMC, or how small the CUMC is. Experimental 

validation of the calculations comes from neutron powder 

diffraction measurements of select MOF-74-D2 systems that show 

excellent agreement.

FIGURE 3: In the upper panel the experimental isosteric heat of adsorption 

(Qst, blue triangles) and the calculated GGA binding energy (EB(GGA) green 

triangles) of the isostructural series of MOF-74 compounds are found to 

behave similarly. In the lower panel the empirical transition metal ion radius 

(r, black squares) and calculated M-H2 distance (d, red filled circles) correlate 

well with d(M-H2) extracted from neutron powder diffraction data (red circles, 

filled white).

In these studies, we have measured the interaction strength 

between a CUMC and di-hydrogen. For this Cu-H2 interaction 

the hydrogen is strongly attached to the metal center as evidenced 

from the small value of the mean-squared displacement parameter 

as compared to hydrogen frozen in the bulk solid. The formfactor of the scattering is well described by the ideal free-rotor 

value without any elongation of the H-H bond. Calculations 

indicate that Coulomb forces dominate the interaction and that 

the hydrogen prefers to lie perpendicular to the Cu-Cu axis of 

the paddlewheel and behave like a quasi-2-dimensional rotor. A 

strong correlation between the size of the exposed CUMCs in 

isostructural MOF-74 framework structures and the resulting 

physical characteristics of interest for hydrogen storage are further 

developed. These observations provide insight in to which metals 

are preferable for incorporating into MOFs for hydrogen storage.

References

[1] S.K. Bhatia, A.L. Myers, Langmuir 22, 1688 (2006). 

[2] M. Dincă, A. Dailly, Y. Liu, C.M. Brown, D.A. Neumann, J.R. 

Long, J. Am. Chem. Soc. 128, 16876 (2006).

[3] Y. Liu, H. Kabbour, C.M. Brown, D.A. Neumann, C.C. Ahn, 

Langmuir, 24, 4472 (2008).

[4] C. M. Brown, Y. Liu, T. Yildirim, V. K. Peterson, and C. J. Kepert, 

Nanotechnology, 20, 4025 (2009).

[5] W. Zhou, H. Wu, T. Yildirim, J. Am. Chem. Soc. 130, 15268, 

(2008).
Chemical Physics

32

Would you like to use a lighter laptop, or a mechanically-flexible portable music player? 

Unfortunately, the lithium-ion batteries used to power these 

devices prevent a light and flexible design. The liquidphase electrolyte requires a rigid casing, making the battery

bulky, heavy and inflexible. Replacing the liquid electrolyte

with a solid polymer electrolyte (SPE) would eliminate

these drawbacks; however, the lithium-ion (Li

+) mobility

through the SPE (quantified as the ionic conductivity)

is insufficient to power a portable device. Polyethylene 

oxide (PEO) is used as the polymer because multiple ether 

oxygen atoms on the PEO backbone can coordinate with

Li+ ions. Ion mobility occurs when Li

+moves from one 

set of ether oxygens to the next. SPEs based on PEO can

contain both amorphous and crystalline regions, and it is

generally accepted that ion mobility is maximized in the 

amorphous regions because polymer mobility is faster. 

However, conductivity through fully crystalline SPEs can

be greater than the amorphous equivalent, owing to the 

formation of cylindrical PEO channels that direct ion 

transport [1]. The cylindrical structure is formed by two

PEO chains wrapped around a column of Li+ ions. Anions 

are required for charge neutrality, and they are located

between the PEO/Li+ channels. This structure is referred 

to as (PEO)6:LiX, where X is the anion. The channels are 

highly conductive at low PEO molecular weight where the

SPE is a powder. When the molecular weight is increased to 

create a flexible solid, the crystalline channels misalign and

the conductivity plummets. Small remnants of the channels

persist in the high molecular weight sample at temperatures 

above the melting point [2]. Together, these results suggest

that structure could be important for achieving high 

conductivity in SPEs, and that portions of the conductive

channels are retained in the high molecular weight sample. 

We use quasi-elastic neutron scattering (QENS) to learn

more about the molecular-level mobility of the (PEO)6:LiX 

remnants [3]. 

 We measure PEO/LiClO4 over a range of Li+

concentrations where conductivity is the highest:

ether oxygen to lithium ratios of 8:1, 10:1 and 14:1. 

Measurements are made at 75 °C where all samples are 

amorphous, and 50 °C where the 8:1 and 10:1 samples are

amorphous. The 14:1 sample is semi-crystalline at 50 °C, and

the crystalline phase is pure PEO. This phase does not contain 

Li

+ ions, and is therefore non-conductive. We use the discchopper spectrometer (DCS) and the high-flux backscattering

spectrometer (HFBS) to measure the mobility of PEO, and 

transform the data to the self-intermediate scattering function, 

S(q,t) (Fig. 1). The DCS data (time shorter than 50 ps) and the

HFBS data (time longer than 200 ps) are combined in Fig. 1 to 

form a single curve. 

FIGURE 1: Self-intermediate scattering function at q = 1.04 Å-1,

(A) 75 °C, and (B) 50 °C. The lines through the data are fits to the 

Kohlrausch-Williams-Watts (KWW) expression.

We focus on the data at times longer than 2 ps, because mobility 

on this timescale is associated with the polymer mobility that

drives Li

+ transport. At 75 °C, polymer mobility decreases with 

increasing LiClO4 concentration, because the ether oxygens are

slowed by their coordination with Li

+ ions. At 50 °C, the 8:1 and 

Molecular Mobility and Ion Transport in Solid Polymer 

Electrolytes For Lithium Batteries

S.K. Fullerton Shirey and J.K. Maranas1

1

The Pennsylvania State University, University Park, PA 16802
NCNR 2009 Accomplishments and Opportunities 33

14:1 samples have the same mobility, because the crystallization 

of pure PEO in the 14:1 sample increases the Li+ concentration to 

8:1 in the amorphous regions. We fit the data at times longer than 

2 ps with a stretched exponential equation, and the fit parameters 

include the relaxation time (τ), the distribution of relaxation 

times (β), and the elastic incoherent structure factor (EISF). The 

data cannot be fit to one process, and we examine each process 

separately. 

The relaxation times for the first process (Figs. 2A and 2B) depend 

on the spatial scale in a way characteristic of the segmental mobility 

that drives Li+ transport (τ ~ q-2/β

). In contrast, the relaxation 

times for the second process are independent of spatial scale 

(Figs. 2C and 2D), signifying a rotational process. Although a 

rotation would not be observed in pure PEO because it has no side 

groups, the addition of Li+ gives rise to a structure where rotation 

could occur: the (PEO)6:LiClO4 remnants. The protons may 

rotate on a circle, where the center of the circle is the axis of the 

cylinder (Fig. 2D). A second process is always reported in SPEs 

where the (PEO)6:LiX structure can form [4,5].

FIGURE 2: Relaxation times for the first (A and B) and second (C and D) 

processes at 75 °C and 50 °C. The line in (A) represents τ1 ∼ q-2.

To characterize the geometry of motion, we examine the spatial 

dependence of the EISF for the second process. We evaluate the 

data at 50 °C because pure rotation is captured at this temperature, 

whereas an additional motion enters the window of the instrument 

at 75 °C (i.e., τ2has a weak q-dependence). The fit lines for the 

second process (Fig. 3A) represent fits to a model that describes 

rotation with a non-uniform distribution, and the angular 

distribution is provided in Fig. 3B [6]. If the rotation results from 

protons wrapped around and coordinated with Li+ ions in the 

(PEO)6:LiClO4 remnants, then we would expect proton rotation 

to be restricted due to PEO chain connectivity and coordination 

with the Li+ ions. Further support is provided by the agreement 

between the radius returned by our fit, and the radius of the 

(PEO)6:LiClO4 structure measured by neutron diffraction (3Å) [2]. 

Fig. 3: (A) EISF versus spatial scale for the second process (B) angular 

probability distribution. The cartoon in (B) represents the probable locations 

of a proton on the circle, where the shading of the proton becomes more 

intense with increasing probability.

We have used QENS to measure the mobility of PEO in PEO/

LiClO4, and attribute the second dynamic process to the restricted 

rotation of protons within remnants of (PEO)6:LiClO4. High 

conductivity has been reported through the (PEO)6:LiX crystal 

structure, and it is possible that the restricted rotation of the 

remnants reflects the local reorganization of ether oxygens to 

accommodate Li+ transport from one set of ether oxygens to the 

next. Understanding transport through the channels is important 

for designing a SPE with adequate conductivity to operate at room 

temperature. 

References

[1] Z. Gadjourova, et al., Nature 412, 520 (2001).

[2] G. Mao, et al., Europhysics Letters 54, 347 (2001).

[3] S.K. Fullerton-Shirey, J.K. Maranas, Macromolecules 42, 2142 

(2009).

[4] G.M. Mao, et al., Nature 405, 163 (2000).

[5] A. Triolo, et al., Physica B. 301, 163 (2001).

[6] M. Bée, Quasielastic Neutron Scattering - Principles and 

Applications in Solid State Chemistry, Biology and Materials Science;

IOP Publishing Ltd: Great Britain (1988).
34Soft Matter

Polymer-based solar cells are a potential source to

convert solar radiation to electric power due to, 

among other benefits, their ease of fabrication, mechanical

flexibility, light weight and low cost. Their performance 

is dictated by the nanoscopic morphology developed 

within a thin (≈ 200 nm) film. In all solar cells, incident 

photons lift electrons into excited states, leaving behind a

positively charged vacancy called a hole. These two opposite

but equally charged particles are initially bound to each 

other through a Coulomb interaction and are collectively

referred to as an exciton. For standard inorganic solar

cells this binding force between the charges is reduced by

the high dielectric constant of the material, thus reducing 

the binding energy and allowing the exciton to dissociate 

readily into a “geminate pair” and the separated charges to

flow to electrical contacts for extraction. 

Organic solar cells are different. Light absorbing polymers 

in these cells, such as poly(3-hexylthiophene) (P3HT) are

poor conductors and have low dielectric constants. Low

dielectric constants lead to tightly bound excitons which, 

coupled with the poor conductivity of the polymer, allow 

the excitons to thermalize and recombine before the charge 

carriers can be separated to flow to the boundaries of the

cell. While polymers such as P3HT absorb almost all

incoming photons within their band gap, the inability to 

separate and extract the created charge carriers is disastrous 

for solar cell performance. For polymer solar cells, this

problem can be combated by the addition of strong electron 

acceptors such as C60 derivative nanoparticles, e.g., phenylC61-butyric acid methyl ester (PCBM), that promote rapid

exciton dissociation into geminate pairs. The dispersion

of acceptors is critical for cell performance, as each exciton

needs an acceptor nearby (≈ 10 nm), while the overall 

acceptor concentration needs to be low enough to facilitate

carrier transport through the solar cell. 

Despite its obvious importance, little reliable information

exists about the dispersion of acceptor nanoparticles in 

organic solar cell films. For example, in the very widely

studied organic solar cell system spin-coated PCBM 

nanoparticles in P3HT, it is well established that a 1:1 mass ratio of

the two components leads to optimum cell efficiency, but it is not

known why that ratio is ideal or if an ideal dispersion is achieved. 

Techniques commonly used for studying the morphology of

thin films such as transmission electron microscopy and x-ray 

reflectometry are totally unsuitable for the PCBM:P3HT system,

as there is virtually no contrast between the nanoparticles and 

the polymer host, and the microscopy in particular is much more

sensitive to local variations in crystallinity than to variations

in nanoparticle concentration. Neutrons however, see strong

contrast between the two components, as PCBM has roughly

a factor of five larger scattering length density (SLD) than does

P3HT. Thus, neutron reflectometry (NR) which is sensitive to the

depth-dependent scattering length density profiles of thin films

is a powerful technique for studying the distribution of acceptor 

nanoparticles. With this in mind we have spin-coated 1:1 

PCBM:P3HT films onto Si substrates, and studied them 

with NR. 

Measurements were conducted at the NG-1 Reflectometer, using 

a silicon “wet cell” sample holder that allows for different backing

layers to be adjacent to the sample surface. Figure 1 shows the 

wavevector (Q) dependent NR spectra for a PCBM:P3HT

film spin coated at 41.7 s-1 (2500 rpm), measured against a 

backing layer of air (green) and D2O (pink). The compositional 

depth profiles of films are commonly determined by fitting a 

sample’s reflectivity to a scattering length density model (using

the formalism of Parratt [2], for example). However, there is a 

significant ambiguity associated with this approach; although 

the depth profile can be uniquely determined from the complex 

reflection amplitude, the measured reflectivity is actually the

square of that reflection amplitude. This “phase problem”

can be overcome by conducting two otherwise identical NR 

measurements with different backing environments, providing 

enough information to allow an exact phase-sensitive neutron

reflectometry (PSNR) determination of the scattering length

depth profile. Alternatively, simultaneous fitting of the same two

data sets to a common model is virtually guaranteed to provide a

non-ambiguous result. 

Film Morphology of Polymer-based Solar Cells

J.W. Kiel1, M.E. Mackay1, B.J. Kirby2, B.B. Maranville2, and C.F. Majkrzak2

1

University of Delaware, Newark, Delaware 19716 2

NIST Center For Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
NCNR 2009 Accomplishments and Opportunities 35

In Fig. 2, we show the results of all three approaches (Parratt 

modeling of the “air” data, simultaneous modeling, and PSNR 

determination) to analyze the NR data shown in Fig. 1. The 

agreement among methods is remarkable, as the scattering length 

density profiles determined by the three techniques each show 

profiles with spikes in scattering length density near the surface 

and substrate interfaces. These spikes indicate a profoundly 

inhomogeneous distribution of PCBM (depicted in Fig. 3), with 

approximately 50 % volume fraction PCBM through the bulk of 

the film, increasing to approximately 80 % volume fraction PCBM 

at the interfaces. 

FIGURE 2: Sample depth profile determined from PSNR (orange), 

simultaneous fitting (green and pink), and Parratt modeling of the “air” data 

(black).

This result [1] clearly demonstrates that the acceptor dopant 

concentration in “optimally” prepared PCBM:P3HT is far 

from ideal, and suggests that striving towards better fabrication 

techniques could result in significantly improved performance for 

this system. 

FIGURE 3: Cartoon depiction of 

the PCBM-rich interface model 

determined from NR. Such an 

inhomogeneous distribution 

of PCBM is not optimal for solar 

cell performance.

References

[1] J. W. Kiel, B. J. Kirby, C. F. Majkrzak, B. B. Maranville, and M. E. 

Mackay, submitted to Nature Nanotechnology, 2009.

[2] L.G. Parratt. Phys. Rev. 95, 359 (1954).

FIGURE 1: Neutron 

reflectivities for the 

sample next to a D2O

fronting (pink) and an 

air fronting (green). 

Lines are fits corresponding to the (Sim. 

Fit) profiles in Fig. 2.
36Soft Matter

Engineering Protein Electrophoresis With the Aid of SANS

D. Pozzo and M. Ospinal1

Twith similar molecular weights in biological settings

is very challenging. Scientists routinely aim to separate 

and quantify the presence of low abundance proteins in

mixtures that may contain several thousands of other 

biomolecules at much larger concentrations. There is a 

pressing need to significantly improve the resolution, 

speed and detection sensitivity of protein separations that 

is motivated by developments in the analysis for proteins

(proteomics) in cells and biological samples such as serum 

and saliva. The identification of low abundance proteins 

in complex mixtures is critical for the development of

technologies such as the early diagnosis of cancer. This need

motivates the continued engineering of new materials and

technologies for proteomic separations so that these may be 

applied routinely, accurately and reproducibly to samples of

increasing complexity. One essential separation technique

is electrophoresis, and small angle neutron scattering

(SANS) can be a great tool to understand and re-design this

technology.

Electrophoresis is the motion of particles relative to a fluid 

under the influence of a uniform electric field. The motion 

allows a mixture of particles to separate over time along

the path of motion according to their speeds of migration.

Electrophoretic separations are well established and their

value to the natural sciences and medical research is widely 

recognized. Of all electrophoretic techniques, sodium

dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE) is by far the most commonly used. In SDS-PAGE, 

an electric field is applied to protein-surfactant complexes

that navigate through a polymeric sieving matrix and

separate. This electrophoretic mobility is controlled by

a variety of molecular parameters including the size and 

conformation of the proteins, the size and geometry of the

sieving matrix and the mode of transport that molecules 

use to navigate through obstacles (e.g., reptation). In SDSPAGE proteins are primarily separated by differences in 

molecular weight. 

In SDS-PAGE, a protein mixture is exposed to heat in the 

presence of the surfactant sodium dodecyl sulfate (SDS) and 

a reducing agent that breaks all disulfide bridges in the proteins, 

opening them out and attaching “pearls” of SDS along the resulting 

chain. This creates a protein-surfactant complex that acquires the 

shape of a “pearl necklace” with surfactant micelles decorating the 

polypeptide backbone (Fig. 1). The solution structure of SDSprotein complexes has been previously investigated with SANS 

[1]. However, the structure and conformation of these complexes 

under actual electrophoretic conditions had not been examined

and remained unknown. SANS can effectively help in investigating

the true molecular conformation of proteins under the application

of electric fields.

FIGURE 1: Denatured protein-SDS complexes form ‘pearl-necklace’ structures 

with discrete surfactant micelles decorating the polypeptide backbone. In 

SDS-PAGE protein surfactant complexes are driven through a polyacrylamide 

network by the application of an external electric field. Proteins are separated 

by molecular weight (blue bands in the gel) because small peptides are able to 

navigate through the gel at a faster rate than longer ones.

Recent developments at the NCNR using contrast variation 

SANS through new sample cells that permit probing of SDSprotein complexes under external electric fields (electrophoresis 

SANS) have allowed exploration of the conformation of SDSprotein complexes inside crosslinked polyacrylamide gels. In these 

experiments, the polymer matrix is contrast-matched through

the use of a mixture of hydrogenated and deuterated monomers. 

The electrophoresis SANS technique was recently applied to the 

analysis of complexes formed with bovine serum albumin (BSA)

and sodium dodecyl sulfate (SDS) in crosslinked polyacrylamide

gels (PAG) with a total monomer concentration of 5 % mass

fraction. The scattering of BSA-SDS complexes in free solution 

is shown in Fig. 2. Analysis is performed using indirect Fourier

transformation methods with newly developed DANSE software

1

University of Washington, Seattle, WA 98195
NCNR 2009 Accomplishments and Opportunities 37

[3]. From the scattering in solution, the ‘pearl necklace’ geometry 

was confirmed and the structural parameters of the protein 

surfactant complex were accurately measured. The technique 

may easily be extended to the study of other biomolecules such 

as DNA and RNA as well as to alternative surfactants and 

polymeric matrices.

FIGURE 2: SANS is used to confirm the ‘pearl-necklace’ structure of bovine 

serum albumin (BSA) proteins in solution. At high Q, the scattering of the BSASDS complex is identical to that of free SDS micelles. Inset: the pair distance 

distribution function (PDDF) after indirect Fourier transformation provides a 

direct measurement of the micelle diameter (40 Å), the average separation 

between micelles (80 Å) and the extension of the complex (250 Å). 

We are now able to probe the transport and conformation of 

biomolecules in real electrophoretic conditions [2]. An electric 

field of 10 V/cm was applied across a polyacrylamide gel that 

separated two reservoirs containing BSA-SDS complexes in 

solution. Figure 3 shows the scattering of the BSA-SDS complexes 

as the total electrophoresis time elapsed and they entered the gel. 

The SANS profiles at short times are similar to those of complexes 

in buffer solutions (compare the white symbol curve to the red 

one in Fig. 2). However, as the electrophoresis time elapsed and 

more proteins enter the gel, the formation of a correlation peak 

indicated the existence of significant interparticle interactions. 

Contrast variation of the surfactant was used to ensure that these 

correlations are only due to BSA-SDS complexes and not affected 

by any ‘free’ micelles. 

The SANS results show that, at these gel concentrations, the 

migration of BSA-SDS complexes occurs primarily through a 

limited fraction of the gel volume that contains relatively large 

pores. This causes a local enrichment of the BSA-SDS complexes 

and the subsequent formation of correlation peaks in the 

scattering. Preferential transport through a fraction of the gel 

volume is a result of heterogeneities or defects that are known to 

occur in crosslinked polyacrylamide hydrogels [4]. Interestingly, 

the scattering of the BSA-SDS samples did not show any sign 

of angular anisotropy when the electric field was applied. This 

suggests that the orientation of the complexes at any instant in time 

is randomized and there is no preferential alignment of proteins 

in the direction of the electric field. Probing of electrophoresis at 

other conditions is necessary to determine if orientation occurs 

when larger monomer concentrations and/or higher electric 

fields are used. These developments enable a more complete 

understanding of the electrophoretic transport mechanisms of 

denatured proteins and provide information to guide the rational 

development of new surfactant and polymeric materials for 

proteomic separations. 

FIGURE 3: The structure factor peaks in SANS profiles of BSA-SDS complexes 

during electrophoresis indicate the existence of significant interparticle 

interactions in the polyacrylamide gel. Contrast variation through the use of 

deuterium labeled surfactants shows that this interaction is due to BSA-SDS 

complexes and not to ‘free’ micelles.

This work demonstrates that SANS can be extremely valuable 

to understand transport mechanisms in gel electrophoresis. 

These experiments have demonstrated the feasibility and value 

of this technique. They have also advanced significantly our 

understanding of molecular transport in the most commonly used 

electrophoresis system of SDS and polyacrylamide matrices. SANS 

experiments are now focused on extending this technique to help 

develop protein separations in which alternative surfactants are 

used. 

References

[1] S.-H. Chen, J. Teixeira, Phys. Rev. Lett. 57, 2583 (1986).

[2] D.C. Pozzo, Langmuir 25, 1558 (2009).

[3] PrView SANS analysis package. http://danse.chem.utk.edu/

prview.html.

[4] A. M. Hecht, R. Duplessix, E. Geissler, Macromolecules 18, 2167 

(1985).
38Soft Matter

Organic semiconductors are the most critical element

of a new generation of optoelectronic devices that 

includes printable flexible electronics and photovoltaic

devices. The vertical distribution and orientation of

crystalline semiconductors in an organic thin film fieldeffect transistor (OTFT) must be controlled by processing 

to achieve optimal switching speed and current flow,

often for a specific OTFT architecture. Common OTFT 

architecture variations involve different placements of the

contacts and gate dielectric. For large-area flexible displays, 

many technology developers prefer a bottom-gated OTFT

over a top-gated one. Gate placement is critical to device 

optimization because charge carriers are formed within 

the semiconductor layer only at its interface with the gate

dielectric. Charge transport occurs within the 6 nm to 

10 nm adjacent to the gate dielectric, and the composition

and orientation of the semiconductor layer at this interface

is critical to device performance.

Formulation and processing are key 

contributors to the character of the organic 

semiconductor layer at the dielectric

interface. Because organic semiconductors 

can be processed from solution, they offer 

advantages over inorganic semiconductors 

such as amorphous silicon, which require 

vacuum. While synthetic advances in recent 

years have produced organic semiconductors

with performance that matches amorphous

silicon, there remain challenges in process

development for methods such as ink jet

drop-on-demand printing, roll-casting, 

and spin coating. A processing challenge

affecting some of the highest-performing

organic semiconductors is that the neat solution viscosity

is too low for common coating methods, preventing the 

formation of high-quality films.

An attractive approach to organic semiconductor

formulation was proposed by Brown et al., who blended 

a high-performance organic semiconductor in solution 

with an insulating polymer binder [1]. Due to the polymer

Organic Semiconductor Polymer Blends For Printable Electronics

binder, the blend solution created high-quality conformal films,

and the films had charge carrier mobility greater than 0.3 cm2

/Vs in

top-gated OTFTs. Because the top-gated mobility was quite high, 

Brown et al. postulated that the semiconducting small molecules

were vertically segregated to the top surface of the thin blend film, 

but no concrete experimental evidence was provided. Although 

this approach represented a significant advance in formulation, the

top-gated architecture is not preferred for large-area displays because 

the active layer can be damaged by subsequent fabrication steps such

as gate electrode patterning and wiring. Instead, the bottom-gate

architecture is favored.

We undertook further development of the blend formulation 

approach to ensure that the semiconducting molecules can also

segregate to a bottom dielectric interface. A critical aspect of this

development was direct measurement of the vertical composition 

profile that can be achieved with nanometer resolution using

neutron reflectivity (NR). Our model blend formulation included 

6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 

poly(α-methylstyrene)(PaMS) (Fig. 1) [2]. Specular NR was used

to measure the vertical composition profile in films spin-coated

onto silicon wafers from solutions of co-dissolved deuterium-labeled

TIPS-pentacene and PaMS. These films provide a model OTFT

film where the native silicon oxide layer mimics the gate dielectric 

interface. The segregation characteristics were controlled by

adjusting the number-average relative molecular mass of the PaMS.

D.M. DeLongchamp1, V.M. Prabhu1, E. Lin1, D.Y. Yoon2

1

Polymers Division, Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 2

Seoul National University, Seoul, Korea

FIGURE 1: Blend formulation materials a) deuterium labeled TIPS-pentacene and b) poly(amethylstyrene)(PaMS) that are used as the active semiconductor layer in an organic thin film fieldeffect transistor.
NCNR 2009 Accomplishments and Opportunities 39

Figure 2a shows the specular NR data for the blend films (50/50

mass ratio) of d-TIPS-pentacene with PaMS of number-average 

relative molecular mass (Mr,n) ≈ 1,300 g·mol-1, spin-cast on a thick 

silicon substrate. In general, the well-defined oscillating reflectivity 

fringes arise from the interference of the reflected neutrons from 

the air and the substrate interfaces, such that the period of the 

fringes is inversely proportional to the film thickness. From the fits 

to the NR data, the scattering-length density (SLD) profiles were

interpreted as d-TIPS-pentacene volume fraction as a function of 

distance from the substrate using the relation: Φd-TIPS × SLDd-TIPS 

+ (1−Φd-TIPS) × SLDPαMS = SLDblend, whereΦd-TIPS corresponds

to the volume fraction of d-TIPS-pentacene. Reference pure 

component films provide the values of SLDd-TIPS and SLDPαMS.

Insets in Fig. 2 show the depth profiles of d-TIPS-pentacene for 

the as-cast film that has a mostly uniform 

distribution of d-TIPS-pentacene with a 

concentration of 51 % volume fraction 

throughout the film thickness, except in the 

two interfacial regions: 11 % excess at the 

blend/silicon substrate and 20 % excess at 

the blend/air interface. Annealing induces a 

further enhanced surface segregation. This 

segregation feature, quantified by neutron 

reflectivity, is consistent with the excellent

field-effect mobility of this blend active 

layer in the top-gated OTFT architectures,

as reported by Brown et al. The bottom 

interface segregation, however, is relatively 

modest and not consistent with expectations 

of high bottom-gated performance as shown 

by comparing the two basic OTFT device 

architectures as insets to Fig. 2.

Figure 2b shows the specular NR data for the blend films (50/50

mass fraction) of d-TIPS-pentacene with PaMS of numberaverage relative molecular mass (Mr,n) ≈ 570,000 g·mol-1. For this 

blend with such a high molecular-mass PaMS, a strong interface 

segregation of TIPS-pentacene occurred in the initial spin-cast 

film. Moreover, the phase-segregated structure formed a nearly 

pure TIPS-pentacene layer not only at the air surface, with ≈ 134

Å thickness, but also at the blend/silicon substrate interface with

≈ 117 Å thickness.

Our results confirm that bottom interface semiconductor 

segregation can indeed be achieved in films cast from blend 

formulations if the binder molecular mass is correctly chosen. We 

observed a segregated layer of nearly pure TIPS-pentacene at the 

blend/silicon substrate interface for high molecular mass PaMS,

but not for low molecular mass PaMS. We confirmed by grazing 

incidence X-ray diffraction that the segregated TIPS-pentacene 

molecules form a highly crystalline structure with the π−π stacked 

molecular layers oriented parallel to the film surface, which is 

important to their semiconducting performance. Finally, we 

measured bottom-gated OTFTs to find that the charge carrier 

mobility, on/off ratio, and threshold voltage of the films cast from 

the high molecular mass blend were significantly superior to those 

cast from pure TIPS-pentacene.

Our approach of using specular neutron reflectivity to measure 

the vertical composition profile in semiconducting blend 

formulations provides a general paradigm for formulation and 

process development in organic electronics. Direct measurement 

of the composition profile identifies processing strategies which 

permit advantageous segregation to the desired device interface. 

This paradigm has a key advantage over the common practice of 

process optimization via solely electrical measurements, because 

the results are far less ambiguous, and the performance results of 

process variations can be more correctly assigned to segregation, 

crystallinity, or other film and device issues [3]. Application of 

this measurement strategy can accelerate formulation and process 

development and hasten the introduction of new products from 

printed, flexible electronics.

References

[1] B.A. Brown, J. Veres, R.M. Anemian, R.T. Williams, S.D. Ogier, 

S.W. Leeming, In International Application Published Under the 

Patent Cooperation Treaty, WO 2005/055248 A2, 2005.

[2] J. Kang, N. Shin, D.Y. Jang, V.M. Prabhu and D.Y. Yoon, J. Am. 

Chem. Soc., 130, 12273 (2008). 

[3] D.M. DeLongchamp et al., Chemistry of Materials, 17 , 5610 

(2005).

FIGURE 2: Neutron reflectivity and vertical composition profiles (insets) of the TIPS-pentacene 

semiconductor for two different blend systems with a) low molar mass and b) high molar mass PaMS 

binder. The relationships among segregations and organic thin film field-effect transistor performances for 

two contrasting device architectures are provided.
40Soft Matter

An important theme in nanoscience is the searchAfor advanced composite materials endowed with 

multiple functionalities. The concept of constructing

multicompartment assemblies emerged in this context, 

drawing inspiration from organized biological systems from 

proteins up to eukaryotic cells [1]. For example, human

serum albumins (HSA) encompass multiple sub-domains 

and combine different environments and functionalities

in close proximity. Suitably designed multiblock polymers, 

such as ABC terpolymers, can spontaneously self-assemble 

into micellar aggregates or gels, in which separate A and 

C nanocompartments are dispersed in a matrix of B plus 

solvent. Potentially, multicompartment assemblies present

opportunities for designing sophisticated storage and delivery

systems, for example to sequester and release different

therapeutic agents in the A and C domains. 

Several groups have constructed multicompartment micelles

in water by dispersing amphiphilic block copolymers 

with two mutually incompatible hydrophobic blocks; the

mutual incompatibility ensuring well segregated domains

inside the core of the micelle [1, 2]. In addition to discrete

assemblies such as micelles, it is of equal interest to design 

multicompartment gels. One route to these novel gels

is to hydrate a linear ABC block terpolymer with a long 

hydrophilic B mid-block and two mutually incompatible, 

but small hydrophobic end-blocks A and C. In our protoytpe

system we examined a solution containing 10 % volume

fraction of a linear terpolymer of poly(1,2-butadiene) (PB),

poly(ethylene oxide) (PEO) and poly(perfluoropropylene

oxide) (PFPO) designated BOF(1.9-26-2.3), where the

numbers in the parentheses denote the molecular weights of

the three blocks in kg mol

–1, respectively. The synthesis of this 

molecule has been documented elsewhere [3].

Cryogenic scanning electron microscopy (SEM) analysis

of the 10 % sample of BOF(1.9-26-2.3) (Fig. 1) revealed a 

bicontinuous structure with the polymer and water dividing

space into two interpenetrating labyrinths. The “pores” (i.e.,

the previously water-filled chambers) have dimensions in

the range 300 nm to 700 nm, consistent with the observed 

opacity of the solution. 

FIGURE 1: Cryo-SEM micrograph for 10 % BOF(1.9-26-2.3) in water at two 

different magnifications.

It is evident that the bicontinuous structure results from the 

arrangement of the strongly hydrophobic end blocks (PB and

PFPO) into space-spanning sheets with non-preferential curvature, 

while the PEO chains apparently shield the hydrophobes from 

water. However, given their appreciably high incompatibility, PB 

and PFPO are also expected to segregate into different domains.

This is subject to the constraint that the volume occupied by

PB blocks is almost twice that occupied by the PFPO block; an

assembly satisfying this constraint features domains of PFPO

dispersed in a PB matrix. From our previous work, where the 

formation of disk-like fluorodomains was a consistent motif, we 

proposed the shape of the fluoro-domains in the hydrophobic 

sheets to be disk-like. The resulting chain packing arrangement is 

illustrated in the cartoon shown in Fig. 2.

FIGURE 2: Proposed chain packing motif for the compartmentalized network. 

PB sheet, PFPO disks and PEO chains are represented in red, green and blue, 

respectively. The PFPO disks could either be (a) thinner than, or (b) extend 

through the PB sheet.

A Compartmentalized Hydrogel from an ABC Block Terpolymer

R.R. Taribagil, M.A. Hillmyer, T.P. Lodge1

1

University of Minnesota, Minneapolis, MN 55455-0431
NCNR 2009 Accomplishments and Opportunities 41

To assess the viability of the microstructure depicted in Fig. 2, 

we carried out small angle neutron scattering experiments on 

the NG-7 30 m instrument at the NCNR. Using two different 

detector settings (1 m and 11 m), we were able to map out the 

scattering profile over a wide range of scattering wave vector q

(0.0039 Å–1 to 0.33 Å–1). Using the principle of contrast matching, 

which involves matching the scattering length density of the 

solvent (a mixture of H2O and D2O) with that of a particular 

block, thus rendering that block “invisible” to the neutron 

beam, we were able to isolate the scattering contributions from 

the different blocks. We estimated the scattering profiles under 

different contrast match conditions and compared them with the 

SANS measurements. It is noteworthy that the complexity of the 

proposed structure, in terms of the number of components present, 

the inherent irregularity, and the probable polydispersity with 

respect to the associated length scales (sheet thickness, disk radius 

and mean spacing, PEO brush thickness, overall pore size) makes 

precise prediction of the scattering profile impossible. But even a 

reasonably good fit, in face of the noted complexities, is convincing 

evidence in support of the proposed structure. 

Details of estimating the scattering profile have been presented 

elsewhere [3]; a brief summary follows. The contributions to 

the scattering equation are the form factors for the PFPO disks, 

the PB sheets, and the PEO brushes, as well as an expression 

to describe the blob scattering from PEO chains. Given the 

bicontinuity of the structure, the low q scattering should be 

dominated by the correlations that exist on 

the length scale of the pore sizes (300 nm 

to 700 nm) estimated from the cryo-SEM 

micrographs. We describe this correlation using 

the single length Debye-Anderson-Brumberger 

(DAB) model for each component. The 

individual contributions from the different 

components as well as the sum of these 

contributions, marked as theoretical curves, 

are depicted in Fig. 3. There is reasonable 

agreement between the model predictions and 

the experimental data, if 14 nm wide and 5 nm 

thick PFPO disks are assumed to be embedded 

in a 5 nm thick PB sheet (Figure 3). A short 

range spatial correlation between the disks 

accounts for the peak near 0.02 Å–1 in all three 

profiles. 

The confirmation of the presence of 

fluorocarbon disks from SANS experiments 

helped us explain the sheet-like morphology in 

the context of the “Super Strong Segregation 

Limit” (SSSL), which is accessed when the 

interfacial tension overwhelms the other 

contributions to the free energy, leading to 

the formation of flat interfaces [4]. The high interfacial tension 

between PEO/water and PFPO encourages formation of flat 

disks. In an interesting interplay between PB and PFPO, the 

fluoro-domains surround themselves with PB blocks along the 

curved surface of the disk to minimize contact with PEO/water 

(the face of the disk serves as an interface between PFPO and 

PEO); the incompatibility between PB and PFPO guarantees 

segregation of both blocks into their respective domains.

In this work we have documented a novel multicompartment 

morphology, obtained by dispersing a linear ABC terpolymer in 

water. This serves to highlight the rich structural possibilities that 

can be obtained from terpolymer gels. The study also highlights 

the power of contrast matching in small angle neutron scattering, 

in partnership with microscopy, to probe intricate details of a 

multicomponent morphology.

References

[1] J. -F. Lutz, A. Laschewsky, Macromol. Chem. Phys. 206, 813 

(2005).

[2] Z. Li, M. A. Hillmyer, T. P. Lodge, Langmuir 22, 9409 (2006).

[3] R. R. Taribagil, M. A. Hillmyer, T. P. Lodge, Macromolecules 42,

1796 (2009).

[4] A. N. Semenov, I. A. Nyrkova, A. R. Khokhlov, Macromolecules 

28, 7491 (1995).

FIGURE 3: SANS intensity 

profiles obtained for (a) PB 

contrast match, (b) PEO contrast 

match, and (c) PFPO contrast 

match conditions. The open 

circles represent experimental 

data, while the dotted and 

solid curves represent model 

predictions.
42Soft Matter

Hydrogels, three dimensional networks of crosslinked 

polymer with high water content, are ideal drug

delivery vehicles for protein delivery. Their highly porous,

aqueous structure provides a biocompatible, solubilizing

environment in which proteins can be encapsulated and

released with both spatial and temporal control to ensure

optimal dosage. Key features of these hydrogels necessary

for therapeutic delivery include their mechanical strength

(i.e., the elastic modulus), kinetics of assembly, structural

stability, and rate of release of the desired therapeutics.

We have engineered hydrogels that are comprised of

self assembled peptides with great potential for delivery

vehicles via the simple modification of the individual

peptide sequence [1]. MAX1 and MAX8 are synthetic

β-hairpin peptides that undergo triggered nanoscale selfassembly to form a physically crosslinked hydrogel network

of fibrils with a defined cross-section, as depicted in Fig. 1. 

FIGURE 1: (A) Peptide sequence of MAX1 and MAX8. (B) Proposed 

mechanism: unfolded peptide under external stimulus folds into 

β-hairpins which self assemble into fibrillar nanostructures that make 

up the rigid hydrogel.

These peptides are freely soluble in aqueous solutions.

However, when a physiological relevant concentration

of salt is added at room temperature, the peptides fold 

into a β-hairpin, and subsequently, self-assemble to form

a rigid hydrogel stabilized by non-covalent crosslinks. 

The sequence of MAX8 is identical to MAX1 with 

the exception of one single amino acid substitution 

(Glu replacing Lys at position 15). This reduces the net

charge on the peptide and results in faster folding and

self assembly kinetics for MAX8 at the same peptide

concentration and identical buffer conditions. These faster

folding kinetics result in more rigid gels, with the modulus

for MAX8 being 2.5 kPa at 1.5 % mass fraction, which is about 

three times higher than for MAX1 at the same conditions [2].

Transmission electron microscopy (TEM) demonstrates that

both peptides form networks of semiflexible fibrils that are 

composed of a bilayer of hairpins [3]. The fibrils are connected 

by non-covalent, interfibrillar junctions and entanglements. 

Imperfections in the self assembly mechanism, in which one 

hairpin is rotated relative to another hairpin in the bilayer, 

can give rise to interfibril branching. Therefore, the increased 

rigidity for MAX8 folded at the same peptide concentration, 

temperature, and buffer is hypothesized to be a consequence

of structural differences either in terms of the topology of the 

network (i.e., more imperfect branch points in MAX8) or in the

compactness of the bilayer (i.e., higher bending constant) [2]. 

Changes to these structural features can play a large role in the

interaction of proteins with the peptide hydrogels and their

subsequent delivery from the sterically hindering network,

emphasizing the need to fully understand these structural 

differences between the two peptides.

In this highlight, we report the first neutron spin echo (NSE) 

measurements of self-assembling peptide hydrogel networks to 

study their dynamics on nanolength and nanotime scales. These 

NSE measurements were designed to explore whether these 

peptide fibrils can be described by the theory of semiflexible

chains on length scales smaller than the persistence length

of the fibrils. In addition, these studies investigated how the

substitution of the Lys at position 15 with a Glu affects the 

nanoscale dynamics to determine whether the observed increase

in viscoelasticity upon peptide substitution is due to a difference 

in nanoscale fibril rigidity. We follow the procedures and 

theoretical analysis defined in recent work on self-assembled 

worm-like surfactants based on the theory of Zilman and Granek 

[4,5]. Complementary small angle neutron scattering (SANS) 

measurements of the networks were also performed to assess any 

differences between the nanoscale structure of the two networks. 

NSE measurements of the peptides demonstrate that the selfassembled peptide fibrils can be described as semi-flexible 

chains on nanolength and nanotime scales [2]. The normalized 

intermediate scattering functions I(q,t)/I(q,0) obtained from 

Dynamics and Structure of Semiflexible, Self-Assembled 

Peptide Chain Networks

M.C. Branco1, J.P. Schneider2, D.J. Pochan3, and N.J. Wagner1

1

Department of Chemical Engineering, University of Delaware, Newark, DE 19716 2

Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 3

Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716
NCNR 2009 Accomplishments and Opportunities 43

the NSE measurements are shown in Fig. 2 for the 1.5 % MAX1 

(A) and MAX8 (B). These normalized intermediate scattering 

functions were fitted for all samples to a stretched exponential 

predicted by the semiflexible chain model, 

I(q,t) = I(q,0) exp(-(Γ(q)t)β

), with Γ(q) = DG q2β. An average β

value of 0.74 ± 0.08 was measured for the peptide gels, which is 

consistent with the predicted value of 0.75 [4], further confirming 

their semi-flexible nature. From the wavevector, q, dependence 

of the scattering, which followed this equation, the segmental 

diffusivity DG decreased upon alteration of the peptide sequence 

from 1.4 x 10-2 (nm8/3 ns-1) for MAX1 to 0.9 x 10-2 (nm8/3 ns-1)

for MAX8. This difference indicates that the fibrils in the MAX1 

network are more mobile on the range of length scales probed, 

which ranges from the fibril diameters to the characteristic mesh 

size, as determined from rheology [1]. This difference in segmental 

diffusivity is consistent with the change in peptide sequence, 

where the Glu at position 15 in MAX8 adds a salt bridge between 

peptides in the self-assembled fibril structure that further stabilizes 

the hairpin structure. However, this difference in mobility is not 

sufficient to fully explain the significant increase in elasticity, and 

therefore, we examined the nanostructure of the network itself. 

FIGURE 2: Normalized intermediate scattering functions for 1.5 % mass 

fraction MAX1 (A) and MAX8 (B) in pH 7.4, 50 mmol/L BTP, 150 mmol/L 

NaCl at 25 °C. Solid lines are fits to a stretched exponential model for 

semiflexible chains. (C) Relaxation rate (Γ(q)) as a function of q. The solid line 

represents the scaling expected for the bending modes of semiflexible chains.

A difference in the number of crosslink junctions between fibrils 

should manifest as a change in the small angle scattering. A look 

at SANS data for MAX1 and MAX8 gels supports this assessment 

[2,6]. As shown in Fig. 3, the scattering for both peptides is 

the same at high q, corresponding to the length scales of the 

individual fibril widths. This is expected as both peptides have 

the same overall length. The spectra differ, however, at lower q,

which probes length scales similar to the nanoscale mesh size of 

the networks. The scattering intensity of MAX8 is significantly 

greater than MAX1 at the same concentration of peptide. The 

increased scattering is consistent with a heterogeneous network 

with a tighter mesh. Indeed, fitting these spectra to Teixeira’s model 

yields apparent fractal dimensions of 1.26 and 1.62 respectively, 

which correspond with the increase in elastic modulus. This 

increase in network junctions for MAX8 is consistent with the 

very rapid rate of self-assembly as compared to MAX1, which is a 

direct consequence of the peptide substitution that lowers the net 

peptide charge [2].

FIGURE 3: SANS intensity I(q) for 1.5 % mass fraction MAX1 and MAX8 (Ref. 

6) hydrogels in pH 7.4, 50 mmol/L BTP, 150 mmol/L NaCl, D2O, 25°C. 

In conclusion, combining NSE and SANS measurements yields 

a physical picture of the nanoscale dynamics and topology of 

these self-assembled peptide hydrogels that is consistent with a 

network of entangled and branched semiflexible fibrils. Through 

controlled modifications of the peptide sequence, we find that the 

nanoscale dynamics can be altered as well as the network topology 

itself. These changes in nanoscale dynamics and structure lead 

to substantial differences in bulk properties, such as the elastic 

modulus [1-3,6]. As shown, analysis of NSE and SANS data with 

models developed specifically for semiflexible polymers enables the 

quantification of the nanoscale properties of these networks and 

the development of molecular structure-property relations. These 

relations enable the rational engineering of peptide sequences to 

synthesize and assemble hydrogels appropriate for specific drug 

delivery applications.

References

[1] M.C. Branco, et al., Biomaterials 30, 1339 (2009).

[2]. M.C. Branco, et al., Biomacromolecules 10, 1374 (2009).

[3] L. Haines-Butterick, et al., Proc. Nat. Acad. Sci. USA 104, 7791 

(2007).

[4] R. Granek, J. Phys. Ii 7, 1761 (1997).

[5] F. Nettesheim and N.J. Wagner, Langmuir 23, 5267 (2007).

[6] R.A. Hule, et al., Faraday Discussions 139, 251 (2008).
44Soft Matter

Biomembranes of natural living cells are made of

phospholipid molecules stacked together into bilayers. 

These membranes are subject to thermal fluctuations in

shape which are governed by membrane stiffness. When

a protein or other molecule is inserted into a membrane

to aid it in fulfilling a biological function, the stiffness 

can be changed, in turn affecting that biological function 

and others mediated by other molecules. Hence, in

understanding biological activity in membranes, it is useful

to measure membrane stiffness, which can be characterized

by a parameter, κc, the bending modulus.

We focus on the effect of a local anesthetic (LA), lidocaine,

for two reasons: 1) it is widely used, and 2) it is an example 

of a small, soluble molecule having hydrophobic and 

hydrophilic parts which in solution finds a membrane and

attaches to it, changing the membrane dynamical properties 

[1,2]. In this article, we highlight results from neutron

spin-echo (NSE), small-angle neutron scattering (SANS), 

and differential scanning calorimetry (DSC) experiments 

on bilayers made of phospholipids with different acyl

hydrocarbons with and without LA. We have investigated

dynamical properties of the membrane as a function of

three factors: (i) the unsaturation of the acyl chains, (ii) the 

bilayer thickness and (iii) the presence of LA.

Membranes made of saturated phospholipids undergo 

a first-order acyl-chain melting transition, the so-called 

main transition from the ripple gel (Pβ’) phase to the liquid

crystalline (Lα) phase, which exists above the freezing

point of water. Lower transition temperatures can be

achieved either by the introduction of the cis double bond

or by having shorter acyl-chain hydrocarbon number in

saturated lipids [3]. Still unclear is how such phospholipid 

conformation changes influence the dynamics of bilayers. 

We have chosen NSE spectroscopy as the most suitable 

method to determine κc, since it is ideal for studies of the

thermal fluctuations of biomembranes because its correlation 

time scale (0.1 ns to 100 ns) and length scale (10 Å to 103 Å)

overlap those of the cell membrane fluctuations.

Seven synthetic lipids of diacyl-phosphatydilcholine 

(PC) having chain-lengths varying from 14 to 20 carbon 

atoms with either zero or one double bond were prepared in 

the form of large unilamellar vesicles (LUV) to investigate the 

dynamic properties of model bilayers. Undulating phospholipid 

bilayers repel each other, so we use the Zilman and Granek 

single membrane fluctuation model [4] to describe the 

scattering. Accordingly, the normalized intermediate scattering 

function I(Q,t)/ I(Q,0), observed by NSE has been fitted 

with the form ( , )/ ( ,0) exp[ ( ) ] 2/3 I Q t I Q =  t , where Γ is the 

relaxation rate which is related to the bending elasticity кc by 

2 3

1

0.025 ( ) Q k T kBT

c

B

k  

 = .

Here, γk is a numerical constant close to unity and c η and kBT are 

the solvent viscosity and the thermal energy, respectively. All

samples were measured in the Lα phase at 60 °C, except for 14:1

PC and 16:1 PC which were measured at 30 °C.

From the mechanics of a thin slab of solid material it is known 

that the bending elasticity κc should scale as the area modulus 

KA multiplied by the square of the thickness d2, i.e., κc = βKAd2

[5], where β is a normalization constant. We speculate that the 

variations of κc in different phospholipid bilayers are due to the

differences in bilayer hydrophobic thickness. As shown in Fig.

1 the elastic ratio κc/KA is indeed proportional to the square

of hydrophobic thickness d2. Here, the area modulus KA and

hydrophobic thicknesses d for these seven lipid bilayers were

quoted from Ref. 5. The dashed line indicates the best fit result 

to a linear function and shows that in a broad range of chain 

lengths (from 14 to 20), either with or without presence of 

one double bond on the hydrophobic chain, κc of lipid bilayers

are quadratically dependent on d. The slope β is approximately

equal to 1/32.2, which agrees well with the results obtained by 

micropipette pressurization [5,6].

FIGURE 1: The ratio of the bending modulus, κc , divided by the area modulus, 

KA , plotted against the square of hydrophobic thickness d2. The labels (e.g.,

18:1 PC) refer to the hydrocarbon number (i.e., 18) in PC and the number of 

double bonds (i.e., 1) in each acyl chain (see Fig. 2).

Dynamics of Biomembranes: Effects of Phospholipid Conformations 

and Presence of Local Anesthetics

Z. Yi1, 2, M. Nagao2, 3 and D.P. Bossev1

1

Physics Department, Indiana University, Bloomington, IN 47405 2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 3

Indiana University Cyclotron Facility, Indiana University, Bloomington, IN 47408
NCNR 2009 Accomplishments and Opportunities 45

LA are weakly amphiphilic bases and may intercalate into the 

bilayer between phospholipid molecules in membranes. Smith and 

co-workers have confirmed that the polar parts of LA interact with 

phospholipid polar fragments and the lipophilic parts of LA insert 

into the bilayer hydrophobic region [7]. As shown in Fig. 2, 

the intercalation, or so-called hydrophobic mismatch between the 

biomembrane and the LA, can induce configurational disorder 

of membranes. Figure 3 summarizes the results of SANS and 

DSC measurements on the 14:0 PC bilayers as a function of the 

molecular ratio R of lidocaine to 14:0 PC. DSC results show 

that the addition of lidocaine progressively depresses the main 

transition temperature Tm of the bilayers. The bilayer thickness was 

calculated from scattering intensities of SANS. The intercalation 

of LA molecules provides more inter-lipid spaces for lipid 

hydrophobic chains, and finally results in the decrease of bilayer 

thickness with the increase of R.

FIGURE 2: 

Model for the 

intercalation of 

lidocaine into 14:0 

PC bilayers. 

FIGURE 3: Transition 

temperature Tm (red 

triangles) and bilayer 

thickness d (black 

circles) of 14:0 

PC bilayers as a 

function of lidocaine 

concentration, R.

NSE has been used to measure the R dependence of κc of 14:0 PC 

bilayers. Figure 4 shows plots of κc of these bilayers with R = 0, 0.5 

and 2.0 in D2O as a function of T - Tm. The effect of temperature 

on κc of pure lipid LUVs in D2O is shown as solid blue circles. For 

T >> Tm,κc of the pure 14:0 PC bilayers is nearly independent 

of temperature, i.e., the temperature has a minimal effect on the 

properties of the lipid bilayer in the Lα phase. As the temperature 

approaches Tm from above for this pure case, κc becomes slightly 

larger and then rapidly increases with decreasing temperature in 

the Pβ’ phase. 

The effect of lidocaine on κc in the Lα phase is small compared 

with its effect on the transition temperature. From our SANS 

result (not shown), it can be demonstrated that the intercalation 

of lidocaine causes a lateral expansion of the membrane, so that the 

tail-tail attractive interaction decreases. The presence of lidocaine 

is thus expected to make the membrane more flexible because of 

decreasing the bilayer thickness. On the other hand, the interaction 

of headgroups increases because of the possible closer packing in 

hydrophilic parts of 14:0 PC and lidocaine. Under the dual effects 

on hydrophobic and hydrophilic groups, the bilayers in the Lα

phase are slightly more rigid due to the intercalation of lidocaine. 

At Tm, κc for R = 0 was found to be 6 times of that in the Lα phase. 

By comparison, κc was estimated to increase only by a factor of 1 to 

3 at Tm for R = 0.5 and R = 2.0. The presence of lidocaine disorders 

the alignment of hydrophobic parts of phospholipid bilayers, thus 

preventing “gelling” at lower temperatures. As shown in Fig. 4, 

below Tm the bending elasticities vary with different slopes in a 

lidocaine-dose-dependent manner. In the Pβ’ phase, the κc value 

is found to be fluctuating from (114.4 to 151.0)kBT and seems to 

be independent of R. This means that the lipid molecules in the 

gel phase are substantially better ordered than in the Lα phase, 

which leads to a significant stiffening of the lipid bilayers. At very 

low temperatures, the thermal undulations of bilayers are greatly 

suppressed and the difference caused by the presence of LA is 

negligible. 

FIGURE 4: κc of a 14:0 PC bilayer with lidocaine concentration R = 0, 0.5 and 

2.0 plotted against T - Tm.

In conclusion, using DSC, SANS and NSE we have examined the 

relationship of bending elasticity κc and hydrophobic thickness 

d of pure bilayers, κc=βKAd2

. Furthermore, we have investigated 

the influence of LA on the structure and dynamics of 14:0 PC 

bilayers. Our results confirmed that LA loosens the packing of 

the membrane constituent lipids and induces lateral membrane 

expansion. The intercalation of LA molecules provides more intermolecular space for the lipid hydrophobic chains and results in 

decrease of the bilayer thickness, a decrease of the main transition 

temperature from Lα to Pβ’ phase, and a slight increase of the 

bending elasticity in Lα phase.

References

[1] Z. Yi, M. Nagao, and D.P. Bossev, J. of Phys: Condens. Matt., 21,

155104 (2009).

[2] Z. Yi, M. Nagao, and D.P. Bossev, (submitted to Biophys. J.). 

[3] G. Cevc, Biochemistry, 30, 7186 (1991).

[4] A. Zilman, and R. Granek, Chem. Phys., 284,195 (2002).

[5] W. Rawicz, K.C. Olbrich, et al., Biophys. J., 79 328 (2000).

[6] H. Bermudez, et al., Langmuir, 20, 540 (2004).

[7] I.C.P. Smith, M. Auger, H.C. Jarrell., Annals of the New York of 

Academy of Sci., 625, 668 (1991).
Earth Science

46

Despite the importance of soil in

sustaining human society, little is 

known about how low-porosity bedrock alters

to high-porosity soil. This transformation

includes physical, chemical and biological

weathering processes that create the partly

altered rock material—regolith—that blankets 

Earth’s surface (Fig. 1). Regolith develops

when bedrock, equilibrated chemically at 

depth in the crust, is exhumed at the surface 

and exposed to water, atmospheric gas, and

biological organisms. Such exposure allows

oxygen, water, acids and organic molecules

to react with minerals in the rock. These 

reactions then drive dissolution, fracturing, 

and disaggregation, allowing penetration of 

more reactants into bedrock. As a result, the

bedrock-regolith interface moves downward

at rates of millimeters to nanometers per year. 

To understand rates of weathering, we need to 

understand the nature of the nano- to macroscale pores, fractures, and rock fragments that 

comprise this interface (Fig. 1). To probe the 

advance of the weathering front, we collected 

rock fragments that span from unaltered 

bedrock up into the weathered zone in three localities, cut 

them into sections hundreds of micrometers thick, and

scattered neutrons through the sections.

Neutrons scatter at an interface if two phases differ in 

scattering length density. Therefore, geologists can use

Small-Angle Neutron Scattering (SANS) and Ultra 

Small-Angle Neutron Scattering (USANS) to investigate 

rock features that range from 10 Å to 10 mm in size [1]. 

Although rocks contain grains of many different

compositions—i.e., minerals—neutron scattering in rocks 

is largely due to the interface between pores and mineral 

grains. Rocks are thus modeled as random two-phase

systems. Furthermore, the different scattering lengths of H

and D can be exploited in contrast-matching experiments 

by mixing a solution of H2O and D2O to match the

scattering length density of the rock. The rock fragment is then 

submerged in the contrast-matching H2O/D2O mixture during 

a scattering experiment, and the resultant neutron scattering

documents only the unconnected pores, i.e., the pores that are 

not filled by H2O/D2O.

We investigated porosity and internal surface area developed 

at the bedrock-regolith interface in three of the most common 

rock types on Earth—granite, basalt, and shale. These silicate

rocks differ in composition (from Na-Ca rich granite to Mg-Fe

rich basalt to Al-rich shale) and grain size (from several tens of 

micrometers in diameter in granite to the micrometer-sized grains

in basalt and shale). The most abundant mineral in the granite and 

basalt is Na,Ca-feldspar, whereas the shale is dominated by illite 

and chlorite clays. In the investigation we explored three types of

samples. The granite was sampled across a fractured weathering

front on bedrock in Puerto Rico [2]; the sample of basalt was the 

Probing the Interface of Bedrock and Soil Using Scattered Neutrons

S.L. Brantley1, L. Jin1, G. Rother2, D. Cole2, A. Navarre-Sitchler1,3

1

Penn State University, State College, PA 16802 2

Oak Ridge National Laboratory, Oak Ridge, TN 37831 3

University of Wyoming, Laramie, WY 82071

FIGURE 1: This schematic of the interface between bedrock and soil demonstrates the complexity 

of regolith—the altered material that blankets bedrock at the Earth’s surface. Porosity in bedrock 

is manifested across the scale from large fractures to sub-nanometer-sized pores. We are 

probing the nanoporosity in unaltered bedrock and in rock fragments collected from within the 

weathered zone to understand the weathering interface.
NCNR 2009 Accomplishments and Opportunities 47

alteration rind on one rock specimen weathered in Costa Rica [3]; 

and the samples of shale were chips recovered from drilled bedrock 

and a soil profile in Pennsylvania [4].

Scattering patterns from granite and basalt are observed to be 

isotropic while scattering from shale is generally not (Fig. 2). 

Azimuthally symmetric scattering spectra in the igneous rocks 

are consistent with random two-phase systems. In contrast, for 

the shale, the anisotropic scattering pattern is consistent with 

cylindrical pores lying within the bedding planes where the shale’s 

clay particles are aligned.

FIGURE 2: Plots of neutron intensity contours from SANS data for (a) granite 

and (b) shale, with brighter colors depicting higher count rates. These figures 

show that scattering is isotropic for the granite and anisotropic for the shale. 

This effect is attributed to roughly equal-sized non-aligned pores in the granite 

and roughly cylindrical and aligned pores in the shale. Scattering from basalt 

thin sections produces intensities that are similar to granite.

For unweathered granite and basalt, the porosity calculated from 

neutron scattering is ≈1.3 % and the surface area is (1 to 3) m2

/g. 

For both rocks, the porosity (Fig. 3) and surface area increase by 

a factor of about 10 across the reaction front where the feldspar 

dissolves. In the reaction zone on the basalt, the porosity that is 

connected increases from ≈ 0.02 % to 1 %. The thickness across 

the zone of feldspar dissolution is ≈ 40 cm in the granite and ≈ 2 

mm in the basalt. 

FIGURE 3: Calculated porosity based on SANS and USANS of samples from 

three rock types collected as a function of position within zones of intense 

weathering. Changes in porosity document the extent of weathering reactions 

such as dissolution of feldspars and clay mineral transformations. The position 

within the weathering interface has been normalized to 1 to enable all data to 

be plotted together (unaltered rock plots at -1, most altered rock plots at 0).

In contrast, the shale has about 4 % porosity when unweathered, 

and this increases to 15 % in rock fragments near the land surface 

(Fig. 3). D2O/H2O contrast matching shows that less than 5 % of 

these pores are connected in the bedrock but 50 % are connected 

in rock fragments in the soil. As weathering proceeds, the specific 

surface area increases five-fold, but in the most highly weathered 

samples near the land surface, the specific surface area decreases 

back toward parent rock values. 

For all three rock types, the scattering intensity varies with the 

size of the scattering object and is consistent with power-law 

size distributions of scattering objects. In both the unweathered 

granite and basalt, the data for scattering intensity versus size of 

scattering object are consistent with two populations of objects, 

each described by a fractal dimension over a wide range in length 

scale. As weathering progresses, the intensity of scattering increases 

but the power-law size distributions do not change markedly. 

Eventually, however, weathering-induced fractures with relatively 

smooth surfaces form in the granite and change the power-law size 

distributions. In contrast, weathering of the basalt and shale are 

not characterized by fractures but are dominated by growth and 

coalescence of pores. Pores in the shale that are probed by SANS 

and USANS are inferred to be pores that are within and between 

clay particles. Trends in surface area and fractal dimensions 

inferred from scattering plots are attributed to coalescence of 

smaller pores into larger pores as well as smoothing of surfaces.

In this research, neutron scattering is revealing for the first time 

the nanoscale character of the interface where bedrock transforms 

to soil. This interface is not a Euclidean plane but is instead 

characterized by rock fragments and mineral grains that are bathed 

in porefluids as well as nanometer-sized pores that are largely 

unconnected in the unaltered bedrock but connected in weathered 

samples (Fig. 1). The weathering interface can be characterized by 

a fractal dimension, and these characteristics change as porosity 

increases during weathering. Conceptual and numerical models are 

now needed to describe how this developing surface controls the 

rates of weathering advance into bedrock.

References

[1]A.P. Radlinski, Ch. 14 in Reviews in Mineralogy and Geochemistry,

vol. 63, Neutron Scattering in Earth Sciences, H.-R. Wenk, Ed., 

Mineralogical Society of America, c. 2006.

[2] H.L. Buss, P.B. Sak, S.M. Webb, and S.L. Brantley, Cosmochim. 

Acta 72, 4488 (2008).

[3] A. Navarre-Sitchler, C.I. Steefel, L. Yang, and S.L. Brantley, J. 

Geophys. Res. 114, F02016 (2009).

[4] L. Jin, R. Ravella, B. Ketchum, P. Heaney, S.L. Brantley, Geochim. 

Cosmochim. Acta, Submitted.
48Instrumentation

MACS -The Multi-Axis Crystal Spectrometer

J.A. Rodriguez-Rivera1,3, D.M. Adler3, P.C. Brand3, C. Broholm2,3, J.C. Cook3, C. Brocker3,

R. Hammond2, Z. Huang3, P. Hundertmark3, J. W. Lynn3, N.C. Maliszewskyj3, J. Moyer3,

J. Orndorff2, D. Pierce3, G. Scharfstein2, S.A. Smee2, R.Vilaseca3 and Y. Zhao2

Through an optimized beam delivery system and a

multi-channel detector, the new Multi-Axis-CrystalSpectrometer (MACS) provides an unprecedented data 

rate for low energy inelastic neutron scattering at NIST. In

a matter of hours MACS can acquire fixed energy transfer 

scattering data through a slice of momentum space. Such 

data determine the atomic scale structure of fluctuating

condensed matter and can for example reveal the effective 

dimensionality and critical wave vector of new magnetic 

materials. Multiple slices can also be assembled to map a 

volume of Q-E space. Alternatively, for low dimensional 

systems, a high resolution Q-E slice can rapidly be obtained 

by pointing the dispersive directions towards the focusing

monochromator and acquiring data versus Ei and 2q. The

unprecedented data rate on MACS offers a unique new 

capability for probing low energy dynamic correlations in

condensed matter. 

MACS presently enjoys a direct view of the NIST cold 

source through the NG-0/CTW beam tube resulting in 

5 x 108 neutrons/cm2/s on the sample at 5 meV (Fig. 1). 

During the shutdown to implement the NIST Expansion,

MACS will move to BT-9 where a new dedicated cold 

source will be brighter and smaller, resulting in lower 

background with similar neutron flux. Down-stream from

the source a rotary beam shutter offers three aperture

options and is followed by a temporary cooled beryllium 

filter. This filter will eventually be replaced by a cryo-filter 

exchange system that will allow cooled beryllium and 

graphite filters to be positioned between the beam shutter 

and the monochromating system. To control energy

resolution, two radial collimators are placed after the

filters. These function as effective horizontal apertures at

the source. The overall beam divergence is controlled by 

vertical and horizontal beam apertures immediately after the

collimators. 

The heart of MACS is the doubly focusing monochromator

(DFM) which consists of an array of 357 PG crystals attached 

to thin aluminum blades which rotate and bend to focus 

horizontally and vertically [1,2]. The monochromator moves 

along the reactor beam to vary the incident energy while minimizing

the corresponding motion of the large detector system. The 

Monochromatic Beam Transport system (MBT) employs m = 3.5 

Ni-Ti supermirrors to guide the monochromatic beam to the sample. 

The MBT channel can be adjusted to accommodate the varying

projected width of the monochromator and sample, and increases

the flux on the sample by up to 25 % [3]. Immediately before the

sample are vertical and horizontal slits to shape the incident beam

and two LiF single crystal attenuators with transmission factors of 

1/10 and 1/100. The sample table is designed for use with high field 

magnet systems with a mass of up to 400 kg.

FIGURE 1: Overview of MACS. The monochromating system includes two 

radial collimators, three filters, a variable beam aperture and a doubly 

focusing monochromator for optimization of Q-resolution, energy resolution, 

and intensity.

The detection system consists of 20 identical channels surrounding

the sample and separated by 8 degrees in the horizontal

scattering plane. Defined by a cast structure formed from B4C in

polyurethane, each channel contains a vertically focusing double

crystal analyzer (DXAL). Each of the two analyzer blades consists 

of 9 PG (002) crystals mounted to form the surface of a cylinder 

with a 50 cm radius. By rotating a single axis for each DXAL,

the selected energy can be varied from 2.3 meV to 15 meV. There

are two detectors in each of the twenty channels. The so-called 

diffraction detector, which views the sample directly, is placed 

behind the first analyzer blade. The spectroscopic detector views 

the second blade, detecting neutrons that satisfy the DXAL Bragg

condition. Now in procurement, a semi-annular cryostat will 

1

University of Maryland, College Park, MD 2

The Johns Hopkins University, Baltimore, MD 21218 3

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
NCNR 2009 Accomplishments and Opportunities 49

provide cooled Be, BeO, or PG post sample filters. Four different 

collimation options (60 ́, 90 ́, 36 ́, and open) will furthermore be 

available for each channel via Soller collimators. 

Quasi-two-dimensional Magnetism in TeVO4

On the very first day of scattering experiments on MACS, 

magnetic Bragg peaks corresponding to commensurate long range 

antiferromagnetic order were discovered in TeVO4. Apart from its 

structure, which indicated the possibility of quasi-one-dimensional 

quantum magnetism, very little was previously known about 

TeVO4 [4]. The rings of inelastic scattering in the (hk0) zone 

and lines along the [1,0,-2] direction detected on MACS (Fig. 2) 

however revealed that TeVO4 is a quasi-two-dimensional magnet 

with weakly interacting ferromagnetic sheets perpendicular to 

(1,0,-2). The experiment illustrates that MACS is a powerful tool 

for an overview of spin correlations in novel materials.

FIGURE 2: Upper figure: TeVO4 structure from Ref. 4. Lower figure: 

Inelastic Q maps at energy transfer ћω = 2.5 meV. With its twenty detection 

channels and high neutron flux MACS allows such data acquisition in hours 

rather than days.

Quantum Criticality in Spin 1⁄2 Chains

MACS can also provide interesting new details in well known 

materials. Figure 3 shows Q-E slices of inelastic scattering from 

the quasi-one-dimensional spin-1⁄2 chain CuPzN [5] at three 

temperatures. High Q-resolution is maintained by pointing the 

spin chains towards the focusing monchromator. Even at low 

temperatures, inelastic scattering in this crystalline material is 

detected through an area of Q-E space rather than along a sharp 

trajectory and this is evidence of a multi-particle neutron scattering 

process. The efficiency of MACS allows each of these data sets to 

be acquired with less than 3.5 h of neutron counting time so the 

full pattern of quantum critical scattering can be probed versus 

temperature. 

FIGURE 3: Maps of inelastic scattering from the quasi-one-dimensional 

spin- 1⁄2 chain CuPzN [5] at three temperatures. Each data set required just 

3.5 h of neutron counting. 

After a long period of planning, designing, engineering, 

manufacturing, and assembly, these two first successful 

experiments clearly indicate that an exciting new tool for 

condensed matter physics has been created in MACS. 

References

[1] C. Broholm, Nucl. Instrum. Methods. Phys. Res., Sect. A 369, 169 

(1996).

[2] S.A. Smee, et al., Nucl. Instrum. Methods. Phys. Res., Sect. A 446,

513 (2001).

[3] J.A. Rodriguez, et al., Meas. Sci. Technol. 19, 034023 (2008).

[4] V. Gnezdilov, et al., Phys. Rev. B. 78, 184407 (2008).

[5] M. B. Stone, et al., Phys. Rev. Lett. 91, 037205 (2003).
50Advances in Measurement

Aprimary concern in elastic neutron scattering instrumental design is to put as many neutrons as possible on the sample

in order to minimize statistical counting errors. On the other 

hand, the need for sufficient measurement resolution generally

means “throwing away” valuable neutrons by tight collimation.

It appears to be commonly believed that these competing

requirements can be mutually accommodated by defining a

number of well-collimated beams simultaneously incident on

the sample at different angles, so that the scattering is measured

simultaneously at different angles (i.e., at different wavevectors 

for a common neutron wavelength). For the general case of nonspecular scattering, however, this means that neutrons counted

at a given angle may well “belong” to different incident beams,

thus requiring a means of sorting out the overlapping reflections

in each detector element. (For ease of presentation, we now

will assume reflection geometry, in particular, and refer to the

desired data as properly normalized reflectivities, i.e., the ratios of

reflected to incident intensities.)

Say there are N incident beams in the multiplex. Then the 

ambiguities of overlapping reflections can be mathematically

resolved by repeating the measurements N times with different

sets of incident intensities, leading to N differently weighted 

(or “modulated”) sums, which can be unwound by solving 

the resulting N linear algebraic equations in the N unknown 

reflectivities, assuming that the N × N matrix (we call it B )

representing the modulated beams is nonsingular. Since a

computer can perform the inversion essentially instantaneously, 

the mathematical aspect of the scheme might appear to be trivial. 

And since there is an apparent statistical benefit to collecting

a sum of sums at each angle, the multiple beam strategy would 

seem to produce the desired effect of combining high resolution 

with reduced counting error relative to performing N singlebeam experiments with the same total number of incident

neutrons.

But is this really so? While the summed data in each detector 

benefit from the usual law-of-large-number effect, retrieving

the contributing reflectivities is not innocuous: because of the

counting errors attached to the actual reflected intensities from

each incident beam, every one of the N N-beam measurements 

introduces N unknown (i.e., uncertain) reflectivities, so the 

algebraic problem actually is one of N equations for N 2

unknowns, which has no unique solution. More precisely, a 

multiplexed experiment consists of N measurements with N

simultaneously incident beams. In the mth measurement, a specific

detector records the sum =

=

N

s

Sm BmsRms

1

for m = 1, 2, ..., N, where Bms is

the intensity of thes

th incident beam in the s 1

mth measurement and Rms

is the noisy reflectivity associated with beam Bms . A nominal inversion

of the vector { } S = Sm is sensibly defined by following our nose and 

definingthe solution as rm ms ms

N

m s

Rˆ(r) (B S)r (B ) B R , 1

1 1

=

= = , for r = 1, 2, 

..., N. In the absence of shot noise, Rms = R,

0s , the “true” reflectivities,

independent of m, and then s R s R r 0 ( ) ˆ = .

To analyze propagation of shot noise, let us define random input

(shot noise) and output (results) “errors”,  ms = Rms R0s and

s s R s r R r 0 ( ) ˆ ( ) ˆ = 

measurements on the same rig, we can also define gross mean square

input and output errors, σin and σout , respectively, by = var 2 

for the appropriate δ, where “var” means the ensemble statistical 

variance and where the overstrike is the average over input and output

channels (i.e., input beams and output results). Then, with the usual 

assumptions about random errors, one can show (with some work) that

out B in = [ ] , where the number

mm mm

N

m

[B] N (BB ) ((B B) ) † 1

1

1 † 

=

 =  (1)

serves as a natural figure of merit for the given beam modulation

strategy.

Clearly from (1) , Ω [B] = 1 for a diagonal matrix—corresponding to

a set of single beam measurements—or for any constant scalar multiple

of a unitary (i.e., here, orthogonal) matrix. Since most real unitary 

matrices have mixtures of positive and negative elements, the latter case

might seem inappropriate for intensity–defined modulations. However,

by applying two distinct modulations, B1and B2, and considering the 

differences of measured Sm for each case, the nominal inversion results 

are those appropriate for the effective modulation, B1– B2 , and such

differential modulation strategies indeed can have matrix elements of

either sign. Thus for diagonal and unitary strategies, σout = σin, and there 

is no shot noise error propagation benefit to multiplexing. But can 

we do better, in terms of error? Are there B for which Ω [B] < 1, so

that σout < σin? We have proven a theorem to the contrary, viz., that 

Ω[B] ≥ 1, and that Ω[B] = 1 occurs only for the aforementioned

matrix classes. Thus, with regard to shot noise propagation, modulated

multibeam measurements of reflectivities can do no better then 

single–beam measurements. Mathematical details and an expanded

discussion of consequences and related issues are given in [1].

References

[1] N. F. Berk and C. F. Majkrzak, Langmuir 25, 4145 (2009).

 Are There Benefits to Multiple Beam Neutron Spectrometers?

N.F. Berk1,2 and C.F. Majkrzak2

1

University of Maryland, College Park, MD 20742 2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
NCNR 2009 Accomplishments and Opportunities 51

This work lays out an x-ray measurement procedure that is able to measure residual stresses with a demonstrated spatial 

resolution of 1 mm × 0.05 mm. Although surface limited, the 

technique is able to solve a variety of measurement problems 

previously reserved for synchrotron x-ray diffraction. The basic 

principle is the use of finely collimated x-ray beams with standard 

– and comparatively inexpensive – x-ray diffraction equipment in 

conjunction with a constant shape and orientation of the beam spot 

on the sample.

Many engineering problems require the knowledge of residual stress 

gradients on a length scale of 1 mm or less which happens to be a 

range very difficult to access nondestructively because of the strict 

requirements for spatial resolution (typically < 10-1 mm). Methods 

and experimental tools exist – such as neutron diffraction, highenergy synchrotron diffraction and conventional x-ray diffraction 

in connection with successive layer removal – but all carry with 

them the disadvantages of high cost and low availability, which 

effectively prevents a routine acquisition of the large amounts of 

data that are often necessary to understand the stress effects of a 

given manufacturing process. However, often overlooked is the fact 

that for stress problems where one or more stress tensor components 

are constant over larger length scales (several mm) the stress 

components of interest are “visible” on the free surface to which 

they are parallel. In this case the experimental requirements are 

much less stringent, since no beam penetration is necessary. It was 

demonstrated in [1] how these conditions can be realized in a simple 

way with high spatial resolution in only one dimension through the 

use of conventional x-ray tubes. 

FIGURE 1: Left: Example (schematic) of a through-thickness stress field that 

can be determined with the technique described in this work. Right: Magnified 

measurement field with rotation δ of the beam spot as the specimen (left) is 

tilted and rotated. 

Diffraction stress analysis is based on measuring lattice strains 

in different directions which requires the specimen surface to be 

tilted and rotated. It is immediately obvious that the x-ray beam 

spot on the surface changes its area and orientation, depending 

on the specimen orientation as shown in Fig. 1. If one poses the 

condition of a constant beam footprint on the sample surface, both 

in orientation and in size, such that the spatial resolution is constant 

in the direction where the stresses change, then the problem has a 

twofold solution: first, a tightly collimated x-ray beam giving the 

desired spatial resolution is required, and second, a path through 

orientation space must be chosen along which that resolution 

remains constant (Fig.1). 

A prime application for this technique is found in automotive sheet 

metal forming where sheet thickness is ≤ 1 mm and residual stresses 

are a key factor for the magnitude of springback (the hard-to-predict 

shape change of a part after a forming or stamping operation). What 

appears to be an arcane side problem actually causes additional 

costs of over $100 million per year in the US alone for tooling 

development. It is thought that advances in materials modeling 

helped by residual stress data will reduce these costs. Figure 2 shows 

the evolution of stresses of a forward-backward- forward-backward 

bending sequence with a bending radius of 5.2 mm which is typical 

for a deep drawing operation using draw beads. 

FIGURE 2: Stresses during a bending-backbending sequence on the high 

strength automotive steel HSLA50. Sheet thickness was 0.8 mm, the height 

of the measurement field was 1 mm (indicated) and the effective spatial 

resolution 0.05 mm.

Additionally, the sheet can be tested in under severe compressive strain 

(≈ 10 %) at the inside of the bent sheet. The level of detail shown in 

Fig. 2 has rarely been seen before, and important insights about the 

magnitude of the Bauschinger effect (essentially the non-symmetric 

distribution of tensile and compressive stresses) become possible. 

References

[1] T. Gnäupel-Herold, J. Appl. Cryst. 42, 19 (2009).

High Resolution Stress Measurements Using In-house X-ray Diffraction

T. Gnäupel-Herold1

1

University of Maryland, College Park MD 20742, and

 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899
Advances in Measurement

52

Neutron Tomography for Advanced Energy Storage

D.S. Hussey and D.L. Jacobson1

Acommon topic in energy systems is the mass transportof hydrogen or hydrogenous materials (such as water 

and electrolyte solutions). Neutron imaging has played

a critical role in the understanding of water transport in 

proton exchange membrane fuel cells (PEMFCs). This 

is due to the high sensitivity of neutrons to hydrogen, 

while having relatively small sensitivity to many common

materials of construction such as aluminum and carbon. 

In addition to the PEMFC research, the NIST neutron

imaging facility is an ideal location for non-destructive,

in situ, mass transport research in three dimensions for

a variety of energy storage systems, including hydrogen

storage beds and a variety of battery chemistries. The 

intense, highly collimated, thermal neutron beam has high 

penetration lengths through the metal hydrides and battery 

chemistries of interest, with sufficient sensitivity to measure

changes in the hydrogen distribution. The high beam

collimation and high resolution imaging detectors (spatial 

resolutions ranging from 250 μm to 10 μm) enable resolving 

features of interest. Two examples of neutron tomography 

demonstrate the use of the technique, hydrogen uptake

in a prototype hydrogen storage bed and the electrolyte 

distribution in an AA alkaline cell during discharge. 

FIGURE 1: Slices through the 3-D image of a hydrogen storage bed 

after the addition of 12 standard liters of H2. Red indicates higher 

concentration of hydrogen, black the absence of hydrogen. (a) Slice 

along the length of the storage bed, (b)-(d) perpendicular slices from 

the locations denoted in (a). Hydrogen uptake decreases with 

increasing temperature which is why hydrogen is seen to preferentially 

absorb along the outer circumference in (a), and accumulate towards 

the end of the storage bed.

The metal hydride bed described in detail in Ref. 1 consisted of

a ≈ 90 % porous aluminum foam filled with LaNi5-xSnx powder. 

Hydrogen gas was introduced into and removed from the bed via 

a hollow stainless steel filter tube in the center. Two tomograms of

the hydrogen storage bed were acquired. The first was after the bed 

was heated to 100 °C and evacuated to a pressure below 10-6 mbar. 

The second was after the bed was charged with about 12 standard

liters of hydrogen. Comparing the empty bed tomogram to the 

bed charged with hydrogen, as shown in Fig. 1, reveals that the

hydrogen preferentially absorbs along the outer circumference. 

In alkaline primary cells, the neutron attenuation is dominated by

the aqueous electrolyte. Tomograms (Fig. 2) of two AA alkaline

cells were acquired before and after discharge to a cell potential of

0 V achieved by two different current draw conditions, 50 mA and 

1 A. The distribution of the electrolyte after the cell potential has 

fallen to 0 V clearly depends on the discharge rate.

FIGURE 2: Comparison of the changes in an alkaline AA cell where black is 

low neutron attenuation, red is high neutron attenuation. (a) and (c) Fresh cell 

before discharge. (b) Discharged cell after operation at 50 mA for 52.5 h.

(d) Discharged cell after operation at 1 A for about 70 min. The electrolyte 

has an initially uniform distribution (green) in the anode (interior) and in the 

cathode (exterior), and the rayon separator (red/yellow) is clearly visible in 

(a) and (c). At the end of life, the electrolyte concentration clearly depends 

on the discharge rate. At lower current, the electrolyte is concentrated at the 

outer circumference of the cathode. At higher current, there is a clear change 

in the electrolyte concentration at the separator boundary.

References

[1] R.C. Bowman, Jr., M. Prina, D.S. Barber, P. Bhandari, D. Crumb, 

A. S. Loc, G. Morgante, J.W. Reiter, and M.E. Schmelzel, Cryocoolers 

12 627 (2003).

1

Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
NCNR 2009 Accomplishments and Opportunities 53

A Phase-Inversion Principle for Neutron Specular Reflectometry

N. F. Berk1,2 and C. F. Majkrzak1

Neutron specular reflection probes the laterally averaged 

scattering length density (SLD) depth profile of thin films. 

Specular reflection can be cast formally as a one-dimensional 

scattering problem (along the x-axis, say), and the power of 

the technique ultimately stems from its resulting mathematical 

coherence, establishing a one-to-one correspondence between 

the reflection amplitude spectrumr k( ) and the SLD ρ(x) that 

produces it (where k is the incident wavevector along x). Thus 

not only is the reflection amplitude unique to its SLD (the 

“direct” problem) but the SLD is unique to its specular reflection 

spectrum (the “inverse” problem) for perfect data. Moreover, 

practical “phase-inversion” methods have been developed for 

determining the reflection amplitude from one or more reflectivity 

measurements and then inverting it, providing a means for reliable 

interpretations of thin film reflection data. We argue that phaseinversion, indeed, sets the limits of informative interpretation.

In more formal terms, the veridical (“true”) ρ induces the veridical 

(or ideal) r, according to a prescription that can be operationally 

denoted by r = rop ρ . In a feasible experiment we measure rˆ, a 

degraded image of r, which, over a large class of ρ, can be 

represented by r D r = op ˆ , where Dop , the degradation operator, 

encodes the deleterious effects of the measurement and phase 

reconstruction process, including counting (shot) noise, Nop , and 

data truncation, K Top, at a finite value of k = K; if these are the only 

degradations, then op

K Dop = Top N . For this class, there is an exact 

solution of the inverse reflection problem, represented by 1

op r , such 

that =  r r op

1 retrieves the veridical SLD from ideal data. If we 

apply 1

op r to the measured rˆ, instead, we obtain ˆ ˆ 1 =  r r op , a 

degraded image of ρ. If rˆ ≈ r in some quantitative sense, then it 

seems reasonable to expect ρˆ ≈ ρ in a similar sense. For example, 

one such sense is that reverting ρˆ to r

ˆ

ˆ, by defining r r op

ˆ ˆ = ˆ,

will produce r ≈ r ˆ

ˆ over the measured k-range. In fact, with some 

important refinements of these ideas, we are led to propose [1] the

Phase-inversion principle: For given ρ(x) − r(k) pair, the 

ρˆ(x) defined by phase-inversion,  ˆ 1 = 

op op op

L

op r T r D r , is 

the best estimate of veridical ρ over any set of measurements on the 

same setup (i.e., for given Dop).

Here L Top denotes truncation over the physical support of the 

film of thickness L. Several factors contribute to the substance 

of the principle. Perhaps the most novel, compared to other 

methods of data analysis, is the distinction between “in-film” 

noise, the effect of propagated shot noise on ρˆ over the thickness 

L, and “out-of-film” noise, viz., the propagated shot noise in 

D r op that lands outside the support of ρ and thus is disposable. 

In effect 1

op

L

op T r acts as a low pass filter, so that the reversion, 

r T r r op

L

op ˆ ˆ

ˆ 1 = , is smoother than rˆ. Another important ingredient 

of the principle is that data truncation, the component T r

K

op , of 

Dopr, represents irretrievably lost information – if one holds to the 

subsidiary principle that only the data at hand determine verifiable 

knowledge of ρ. A priori knowledge (i.e., additional assumptions 

about ρ) can not inform us about unmeasured data, viz., “data” 

beyond the cutoff K.

FIGURE 1: (a) Efficient averaging over N results , for N=1,..,100,

for a model film [1]; dotted line, N = 100; red line, N = 10. (b) Inset: ESTDMN

is the point-wise estimated standard deviation averaged over x.

The statistical analysis of phase-inversion is discussed extensively 

in [1]. Among the more surprising findings is the efficiency of 

averaging over a set of inversions m N {ˆ } for N measurements on 

the same setup. The average N ρˆ converges exponentially faster 

to the true average ( N → ∞ ) than the expected 1/ N rate. 

Even 

10 ˆ is remarkably close to the large-N average, as shown 

in Fig. 1. This accelerated convergence is, in part, a benefit of 

disposable out-of-film noise and further illuminates the statistical 

underpinnings of the phase-inversion principle.

References

[1] N. F. Berk and C. F. Majkrzak, Langmuir 25, 4132 (2009).

1

University of Maryland, College Park, MD 20742

2

NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
54Neutron Source Operations

Neutron Source Operations

The NIST reactor (NBSR) operated for 244 full power (20 MW) days or 99 % of the scheduled time 

during FY2009. A typical operating year consists of seven

cycles. A cycle has 38 d of continuous full power operation 

followed by 11 d of shutdown for maintenance, refueling,

and startup preparations. This outstanding record of safe

and reliable performance of the reactor and cold source lies 

at the foundation of the success of the neutron scattering, 

nuclear methods, and neutron physics programs. The 

Nuclear Regulatory Commission issued a 20 year license 

renewal on July 2, which permits operation of the reactor to 

2029. Some of the activities of the Reactor Operations and 

Engineering Group are outlined below.

FIGURE 1: Operations Electrical Engineer Dennis Brady inspects the 

status indicator on a newly installed Motor Control Center.

Facility Improvements

v Shim Arm Replacement: The NIST Reactor is 

controlled by shim arms, which consist of neutron

absorbing cadmium, lodged between two supporting 

aluminum tubular structures. The cadmium gets 

depleted (“burned”) in the process of controlling the

reactor, which requires the periodic replacement of

the shim arms. This complex project was completed

without incident early in the fiscal year. An improved 

drive mechanism has been designed by the group and

a contract has been signed to provide replacement 

shim arms for the duration of the reactor license.

FIGURE 2: Cask is aligned in a spent fuel transfer operation.

v Leak Detector Panel: The reactor’s heavy water coolant/

moderator is an expensive resource and an extensive

detection system monitors for leakage of any water. The 

original analog panel has been replaced with a computer 

controlled system which allows the control room operators 

to more quickly assess the duration and location of potential 

leakage.

v Electric Panel Upgrade: All motor control centers 

associated with the reactor systems have now been replaced

with state of the art units. The new units allow the NCNR 

increased reliability and several special features including 

relaying the status of the motor control centers directly to

the reactor control room. 

New Staff

The Reactor Operations and Engineering Group hired several new 

staff members this year. One senior reactor operator candidate,

Andrew Blazek, is scheduled to be licensed by the summer of 2010.

Two experienced nuclear engineers, Daniel Hughes and Sean 

O’Kelly were also brought on board in 2009. Our group is very

pleased to welcome these able new staff members to the NCNR.

FIGURE 3: New Reactor Operations and Engineering staff members Andrew 

Blazek, senior reactor operator candidate, Dan Hughes, nuclear engineer, 

and Sean O’Kelly, nuclear engineer.
NCNR 2009 Accomplishments and Opportunities 55

Facility Development

The NCNR is entering a period of unprecedented activity 

of facility expansion and upgrades that will deliver longterm gains and satisfy the changing needs of the user community. 

During the past year construction of the guide hall extension 

and support buildings has begun and NCNR engineering efforts 

have focused on integrating the new guide hall with the existing 

experiment hall and the design, construction, and installation 

planning for the suite of new guides, new instruments, and a reoptimized instrument layout. 

NCNR Expansion

The new guide array (shown schematically in Fig. 1) will view 

the current liquid hydrogen cold source through the beam port 

currently occupied by the MACS spectrometer. All the new 

guides utilize the latest high-reflectivity supermirror coatings and 

include a curved section at the source end followed by a straight 

section. The curved sections permit five new beamlines to be 

extracted from the restricted angle of the beam port and have the 

added advantage to reduce or eliminate the need for crystal filters 

upstream typically required in straight guides to remove unwanted 

short wavelength neutrons and gamma rays. 

Installation of the full guide system involves precision alignment 

of over 350 individual glass guide modules including many with 

quasi-elliptical cross-sections. To expedite this complex process, 

facility engineers and technicians have been working on dedicated 

procedures to utilize state-of-the-art laser tracking alignment 

systems. Adopting this new technology offers highly accurate 

alignment of individual guide components in three dimensions 

during the installation process while promising benefits in future 

for maintenance and operation. In particular, the laser tracker 

system allows for easy replacement of guide components and 

re-verification of their positions in case of ground settlement, and 

allows remote alignment in areas of potentially elevated radiation. 

Design work has been initiated on vSANS – the first of five new 

instruments in the expansion program. The vSANS instrument 

will be a highly versatile and unique instrument offering an 

extended q-range (2.0 x 10-4 < q < 0.7 Å-1) thus bridging the 

gap between conventional SANS and uSANS instruments. The 

design includes both multiple converging pinhole and multiple 

converging slit geometries and is optimized to take advantage of 

the present large neutron guide at NG-6, thus offering appropriate 

intensity for the measurements. 

Progress with existing instrumentation, software, and sample 

environment equipment at the facility continues to be made in 

parallel with the expansion activities and recent developments are 

described below. 

Instrument Development

The Multi-Axis Crystal Spectrometer (MACS) is the most recent 

addition to the suite of advanced cold-neutron instruments 

provided by NCNR. During the fall of 2008 the MACS 

FIGURE 1: Design 

drawing showing the 

5-guide array in the 

new guide hall viewing 

upstream to the cold 

neutron beam port 

NG-0. The instruments 

shown are (r-l): NSE; 

10 m & 30 m SANS; 

Physics Station; MAGIK 

reflectometer. 
56Facility Development

analyzer was installed at NG-0 and this year has seen the 

landmark first scattered neutrons to be recorded by the

novel detection system comprising twenty independent

monochromatic channels. The performance of MACS, in 

particular the complex analyzer system, is presently being

evaluated and optimized as the instrument enters a period

of rigorous commissioning activities. Even at this early 

stage, the unique capabilities of MACS in the area of coldneutron spectroscopy can be seen (see pp. 48–49) and the

new spectrometer has been shown to record publication

quality data and outperform traditional triple axis 

instruments on previously measured specimens. As part of 

the NCNR expansion program MACS will relocate within

the confinement building to BT-9 and view a dedicated 

new cold source – offering still further increases in cold 

neutron flux albeit across a smaller beam size. Design and

fabrication of the new cold source has now been completed

along with successful proof testing of all components. 

Progress has also been made with the TISANE project,

funded through the Center for High Resolution Neutron 

Scattering (CHRNS), to develop the new experimental

Fourier method of Time dependent SANS Experiments. 

The technique provides for microsecond time resolution

without a major sacrifice in intensity by making use of very 

large frame overlap and complements recent progress with

time resolved small angle x-ray scattering. The fast chopper,

pre-requisite for the TISANE technique, was installed on

the NG-7 SANS instrument along with timing and control

electronics for the detector system. This equipment will 

permit dynamic studies of phenomena occurring on time 

scales of 50 μs to 150 ms by time-resolved stroboscopic 

SANS. Commissioning measurements on a range of

optically and magnetically excited systems will begin in late 

Summer 2009. 

Instrument Control and Software Development

This year the NCNR continued a program of

instrumentation upgrades intended to bring all NCNR 

instruments in compliance with facility standards

and to prepare them for migration to the Instrument

Control Environment (ICE) software system. The ICE 

software package, currently operating on the triple axis 

spectrometers BT-7 and MACS, has now been extended

and is under release on the SANS instruments NG-3 and

NG-7. As part of the migration, both SANS instruments

have been recipients of motion controls and histogramming

upgrades. Tangible improvements over the legacy VMS 

controls and software include faster collection times,

reduced overhead, real-time detector overcount protection,

and greatly increased functionality for data acquisition through

scripting. 

Given the remarkable reliability record of the NIST reactor 

and cold source, efforts are continually being made to improve 

instrument reliability. To this end, the facility infrastructure 

monitoring system has been upgraded to use readily deployable

remote sensing modules so that more monitoring points, for 

example guide vacuums, chilled water temperature and pressure,

and other, instrument-specific quantities, can be accommodated. 

The new system has enhanced facilities allowing condition 

monitoring of equipment and fault notification. Using this

information in targeted maintenance activities and for rapid fault

diagnosis helps minimize instrument down time. 

Data Analysis Software Development

DAVE is the NCNR multi-platform software suite, tailored

particularly for non-expert users, designed to rapidly and easily

view and interpret experimental data. Following the release last 

year of DAVE 2, designed around the IDL iTools framework, 

efforts this year have focused on consolidating the application

core and taking advantage of the new framework. For example, 

improved interactions between program modules now enable

sophisticated visualizations to be generated with a single mouse 

click and numerous data manipulation operations are now 

implemented as self-contained components that are globally

available and share a standard interface. 

FIGURE 2: DAVE visualization of the Fourier density map (F observed) and 

corresponding atomic positions for a simple spinel structure.

The development of DAVE continues to be responsive to user

requests and new modules are added regularly. A recent example 

is 3DenPro (see Figure 2) which uses the built-in volume 

visualization capabilities to display unit cell information computed 

from crystallography experiments; the application module displays

the atoms and bonds, unit cell outlines, and Fourier densities.
NCNR 2009 Accomplishments and Opportunities 57

Sample Environment

NCNR personnel support a diverse range of ancillary sample 

environment equipment and promote development activity 

in a number of areas. In response to user demand, a bottomloading close-cycle refrigerator (CCR) operating over an 

extended temperature range from 25 K and up to 900 K has 

been commissioned for general use across the facility. The CCR 

also boasts a rapid cool down from ambient to base operating 

temperature allowing for more efficient use of beam time. New 

high-pressure cells have also been acquired in response to 

significant growth in experimental programs utilizing the recently 

commissioned 1.36 MPa helium gas intensifier system. The 

aluminum and stainless steel cells reliably and routinely operate 

down to low temperature and up to pressures of 0.65 MPa and 

1.00 MPa, respectively. 

FIGURE 3: NCNR’s Juscelino Leão prepares a complicated sample 

environment installation for a DCS experiment.

New equipment introduced this year includes a low-temperature 

10-postion sample changer designed for the SANS instruments 

and capable of operating down to approximately 200 K. Options 

for low-temperature SANS experiments have been enhanced 

further with the outfitting of a liquid helium cryostat dedicated for 

specific use on the SANS instruments. 

In late 2009, the facility will take delivery of a new dilution 

refrigerator and cryostat assembly operating down to 20 mK. The 

new refrigerator will increase both the capacity and also reliability of 

low-temperature operations and is primarily for use supporting user 

programs on the triple-axis and spin echo instruments. Delivery of a 

new rheometer for the SANS user program is also expected and will 

update and expand significantly the capability for rheology using this 

technique. 

A major focus of development activity continues on 3He neutron 

spin filters (NSFs). This program, run in collaboration with the 

Physics Laboratory at NIST, has provided 3He NSFs that are now in 

routine use for polarized beam experiments on the thermal neutron 

triple-axis spectrometer BT-7 in addition to small-angle neutron 

scattering instruments and reflectometers. Neutron spectrometers 

present some challenging spatial constraints for the spin filter 

setup and there is a constant drive towards miniaturization of the 

apparatus. This year the team has successfully produced a reduced 

length “Magic Box” for use on BT-7 and NG-3. This device is 

the magnetostatic cavity that provides a homogenous magnetic 

field over the 3He cell while providing shielding from stray fields 

thus promoting longer polarization 3He lifetimes. By introducing 

compensation sections tuned to limit end effects of the box the 

new devices meet a length constraint on key NCNR instruments of 

29 cm compared with 37 cm of previous designs while retaining the 

large, 10 x 15 cm2, cross-sections required by the cells.

A further challenge being addressed is to develop a compact 

system for wide-angle polarization analysis for use on MACS: 

here the polarizer, analyzer and any spin flippers must fit within 

a region surrounding the sample of only 40 cm diameter while 

also accommodating a typical cryostat tail of 13 cm diameter. An 

unshielded solenoid wound with aluminum wire, dimensioned for 

the MACS sample stage, has now been produced to provide the 

uniform field for the 3He cells and serve as the guide field for the 

polarized neutrons. A miniature, radio-frequency shielded solenoid 

has also been constructed that enables efficient inversion of the 3He 

polarization in the polarizer without affecting the analyzer. To cover 

the full detector angular range on MACS, two fused quartz analyzer 

cells, on opposite sides relative to the incident neutron beam will be 

used to cover a total angular range of 240  ̊. The analyzer cells, as 

well as the simple polarizer cell, are polarized off-line using the wellestablished spin-exchange optical pumping (SEOP) method prior 

to installation on the beamline. Offline tests of this novel apparatus 

have shown promising results and polarized beam experiments 

on MACS are keenly anticipated as part of the instrument 

commissioning program. 

User Laboratories

The program to improve and renovate the NCNR laboratories 

used by both visitors and staff continues. This year saw the 

acquisition of a thermal gravimetric analyzer and refurbishment 

of laboratory space in support primarily of research programs on 

hydrogen storage materials. The TGA was purchased through a 

DOE grant awarded to the hydrogen storage group at the NCNR.
58Serving

The mission of the NIST Center for Neutron Research is to assure the availability of neutron measurement capabilities

to meet the needs of U.S. researchers from industry, academia and

from other U.S. government agencies. To carry out this mission, the 

NCNR uses several different mechanisms to work with participants

from outside NIST, including a competitive proposal process,

instrument partnerships, and collaborative research with NIST.

Proposal System

Most of the time on NCNR instruments is made available

through a competitive, peer-review proposal process. The

NCNR issues calls for proposals approximately twice a year. 

Proposals are reviewed at several different levels. First, expert

external referees evaluate each proposal on merit and provide

us with written comments and ratings. This is a very thorough

process where several different referees review each proposal.

Second, the proposals are evaluated on technical feasibility 

and safety by NCNR staff. Third, we convene our Beam Time

Allocation Committee (BTAC) to assess the reviews and to

allocate the available instrument time. Using the results of the 

external peer review and their own judgment, the BTAC makes 

recommendations to the NCNR Director on the amount of 

beam time to allocate to each approved experiment. Approved

experiments are scheduled by NCNR staff members in 

consultation with the experimenters. 

The current BTAC members are:

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Partnerships

The NCNR may form partnerships with other institutions to 

fund the development and operation of selected instruments. 

These partnerships, or “Participating Research Teams”, may have

access to as much as 75 % of the available beam time on the 

instrument depending on the share of total costs born by the 

team. A minimum of 25 % of the available beam time is always 

made available through the NCNR proposal program to all users. 

Partnerships are negotiated for a fixed period (usually three years) 

and may be renewed if there is mutual interest and a continued need. 

These partnerships have proven to be an important and effective way to

expand the research community’s access to NCNR capabilities and have 

been very successful in developing new instruments.

Collaboration with NIST

Some time on all instruments is available to NIST staff in support 

of our mission. This time is used to work on NIST research needs,

instrument development, and promoting the widespread use of neutron 

measurements in important research areas, particularly by new users. As

a result of these objectives, a significant fraction of the time available to 

NIST staff is used collaboratively by external users, who often take the

lead in the research. Access through such collaborations is managed

through written beam time requests. In contrast to proposals, beam 

time requests are reviewed and approved internally by NCNR staff. 

We encourage users interested in exploring collaborative research

opportunities to contact an appropriate NCNR staff member.

Research Participation at the NCNR

The NCNR continued its strong record of serving the U.S. research 

community this year. Over the 2009 fiscal year, 2290 research

participants benefited from use of the NCNR. (Research participants 

include users who come to the NCNR to use the facility as well as active 

collaborators, including co-proposers of approved experiments, and 

co-authors of publications resulting from work performed at the NCNR.)

Research participants represented 220 external institutions, including 142 

U.S. universities, 32 national laboratories, and 46 U.S. industries. 

The NCNR is a national facility, with participants from 41 states, DC, 

and Puerto Rico. 

FIGURE 1: Research participants at the NCNR 1987- 2009

2009 NCNR Proposal Program

Two calls in the past year resulted in the submission of 680 proposals, 

a record number, of which 418 were approved and received beam time. 

Serving the Science and Technology Community
NCNR 2009 Accomplishments and Opportunities 59

The oversubscription, i.e., the ratio of days requested on all proposals to 

the days available, was 2.1 on the average, but as high as 3.3 for specific 

instruments in one call. Proposal demand has grown constantly since the 

NCNR first began accepting proposals in 1991, and has doubled in the 

past seven years. The following table shows the data for several instrument 

classes.

Instrument class Proposals Days requested Days allocated

SANS and USANS 261 977 466

Reflectometers 107 814 418

Spectrometers 270 1831 820

Diffraction 21 78 58

Imaging 31 147 68

Total 698 3847 1830

User Group Plans Third Election

The NCNR Users Group (NUG) provides an independent forum for 

all facility users to raise issues to NCNR management, working through 

its executive officers to carry out this function. In early 2007, it conducted 

a comprehensive online survey of user satisfaction and concerns, eliciting 

260 responses with many useful comments on areas such as instrument 

quality and problems, sample environment, data analysis software, and 

user laboratories. The survey input is being used as a guide to make 

some significant improvements in user support. In December 2009, 

the NUG will conduct its third online election of officers. The current 

NUG Executive Committee members are Stephan Rosenkranz (Argonne 

National Laboratory, chair), Mark Dadmun (University of Tennessee, 

Knoxville, vice-chair), Kalina Hristova ( Johns Hopkins University), 

Moon Jeong Park (University of California, Berkeley), Tonya Kuhl 

(University of California, Davis), Robert Leheny ( Johns Hopkins 

University), and Lynn Walker (Carnegie-Mellon University).

Panel of Assessment

The major organizational components of NIST are evaluated periodically 

for quality and effectiveness by the National Research Council (NRC), 

the principal operating agency of both the National Academy of Sciences 

and the National Academy of Engineering. A panel appointed by the 

NRC reported on the NIST Center of Neutron Research in January 

2008 and again in January 2009. The findings from a 2008 assessment are 

summarized in a document that may be viewed online at http://

www.nap.edu/catalog.php?record_id=12495. The panel members 

included Tonya Kuhl of the University of California, Davis (chair), 

Frank Bates, University of Minnesota, Stuart Bush, Rohm and Haas 

Corporation, Donald Engelmann, Yale University, Christopher Gould, 

North Carolina State University, Alexander Grosberg, New York 

University, Sunil Sinha, University of California, San Diego, and Barbara 

Wyslouzil, the Ohio State University.

The Center for High Resolution Neutron 

Scattering (CHRNS)

The CHRNS is a national user facility that is jointly funded by the 

National Science Foundation and the NCNR. Its primary goal is to 

maximize access to state-of-the-art neutron scattering instrumentation 

for the research community. It operates six neutron spectrometers and 

diffractometers at the NCNR, enabling users from around the nation 

and the world to observe dynamical phenomena involving energies from 

≈ 30 neV to ≈ 100 meV, and to obtain structural information on length 

scales from 1 nm to ≈ 10 μm. A more detailed account of CHRNS 

activities may be found on pp. 60–61 of this report.

Partnerships for Specific Instruments 

NG-7 SANS Consortium

A consortium that includes NIST, the Industrial Partnership for 

Research in Interfacial and Materials Engineering (IPRIME) led by the 

University of Minnesota, and the ExxonMobil Research and Engineering 

Company, operates, maintains, and conducts research at the NG-7 30 m 

SANS instrument. The consortium uses 65 % of the beam time on this 

instrument, with the remaining 35 % allocated to the general scientific 

community through the NCNR’s proposal system. Consortium members 

conduct independent research programs primarily in the area of largescale structure in soft matter. For example, ExxonMobil has used this 

instrument to deepen their understanding of the underlying nature of 

ExxonMobil’s products and processes, especially in the fields of polymers, 

complex fluids, and petroleum mixtures. 

NIST / General Motors – Neutron Imaging

An ongoing partnership between General Motors and NIST has resulted 

in an exciting collaboration employing neutron imaging to visualize 

the operation of fuel cells for automotive vehicle applications. Neutron 

imaging is an ideal method for observing the movement and behavior 

of water in proton exchange membrane fuel cells, a key to developing 

hydrogen-powered cars that employ such cells instead of internal 

combustion engines as their central power source. In the past year, the 

spatial resolution of the technique has been improved yet again to a value 

approaching 10 m. Experiments were performed to understand and 

optimize fuel cell performance at temperatures approaching -40 °C, a 

necessary advance towards development of robust fuel cell vehicles.

Interagency Collaborations

The Center for Food Safety and Applied Nutrition, U.S. Food and Drug 

Administration (FDA), directs and maintains a facility at the NCNR that 

provides agency-wide analytical support for food safety and food defense 

programs. Neutron activation (instrumental, neutron-capture promptgamma, and radiochemical), x-ray fluorescence spectrometry, and lowlevel gamma-ray detection techniques provide diverse multi-element and 

radiological information about foods and related materials. Ongoing work 

includes studies of cryogenic homogenization of foods, improved detection 

capabilities for toxic and nutritional elements in foods, and rapid screening 

of food products for dangerous levels of cadmium, lead, and mercury in 

beverages and residual bromine in baked goods. Recent studies include 

the preparation and characterization of a swordfish in-house reference 

material.

The Smithsonian Institution’s Nuclear Laboratory for Archeological 

Research is part of the Anthropology Department at the National 

Museum of Natural History. It has had a productive 32 year partnership 

with the NCNR, during which time it has chemically analyzed over 

39,000 archaeological artifacts by Instrumental Neutron Activation 

Analysis (INAA), drawing extensively on the collections of the 

Smithsonian, as well as on those of many other institutions in this country 

and abroad. Such chemical analyses provide a means of linking these 

diverse collections together in order to study continuity and change 

involved in the production of ceramic and other artifacts.
60CHRNS

CHRNS is a national user facility that is jointly funded 

by the National Science Foundation, through its 

Division of Materials Research (grant number DMR0454672), and by the NCNR. The primary purpose of this 

partnership is to maximize access to state-of-the-art neutron

scattering instrumentation for the research community

through the NCNR’s proposal system. Proposals to use the

CHRNS facilities are critically reviewed on the basis of

scientific merit and/or technological importance.

The core mission of CHRNS is fourfold: (i) to develop and

operate neutron scattering instrumentation, with broad 

application in materials research, for use by the general

scientific community; (ii) to promote the effective use of the 

CHRNS instruments by having an identifiable staff whose

primary function is to assist users; (iii) to conduct research 

that advances the capabilities and utilization of CHRNS

facilities; and (iv) to contribute to the development of

human resources through educational and outreach efforts.

Scattering Instruments and Research

CHRNS currently operates six instruments: the 30-meter 

Small Angle Neutron Scattering (SANS) instrument at

NG-3, the Ultra-Small Angle Neutron Scattering (USANS) 

instrument at BT-5, the Spin-Polarized Inelastic Neutron

Scattering (SPINS) spectrometer at NG-5, the Disk 

Chopper Spectrometer (DCS) at NG-4, the High Flux

Backscattering Spectrometer (HFBS) at NG-2, and the 

Neutron Spin-Echo (NSE) spectrometer at NG-5.

The small angle scattering instruments supported by

CHRNS provide structural information over length scales 

from ≈ 1 nm to ≈ 10 μm. The spectrometers collectively 

yield dynamical information over time scales from 

≈ 3✕10-14 s to ≈ 10-7 s (energy scales from ≈ 100 meV to

≈ 30 neV). These wide ranges of accessible distances and 

times support a very diverse scientific program, allowing 

researchers in materials science, chemistry, biology, and

condensed matter physics to investigate materials such as

polymers, metals, ceramics, magnetic materials, porous

media, fluids and gels, and biological molecules. 

In the most recent Call for Proposals, 246 of the 359

proposals received were for the six CHRNS-operated

instruments. One hundred and twenty-eight of the 256

were awarded beam time. Of the 1291 days requested, the

Beam Time Allocation Committee approved 569. Roughly

half of the users of neutron scattering techniques at the NCNR

use CHRNS-funded instruments, and more than one third of

NCNR publications (see the “Publications” section on p. 64) over

the current one-year period are based on research performed using 

these instruments. In 2008 more than twenty Ph.D. theses were 

completed using results from CHRNS-sponsored instruments. 

Two of these received awards (Matthew Helgeson (University of

Delaware) from the Neutron Scattering Society of America for

Outstanding Student Research, and Susan Fullerton Shirey (Penn

State University) from the American Physical Society was selected 

for the Frank J. Padden, Jr. award for Excellence in Polymer Physics

Research.)

Scientific Support Services

An important ingredient of the CHRNS operation is its support

of staff whose responsibility is to provide services that are essential 

to the success of neutron scattering investigations. One such 

service is the provision and operation of an expanding range of

sample environment equipment. The sample environment team 

often takes on projects to expand the range of existing equipment,

enhance its safety, improve its reliability, and even develop

entirely new capabilities. For example, a top-loading closed-cycle 

refrigerator has been specifically designed for use on the NSE 

spectrometer.

Other services include the maintenance of several well-equipped 

user laboratories, and the development, documentation and

maintenance of data reduction, visualization, and analysis

software through the DAVE project. DAVE is a suite of programs

that enables users to rapidly reduce, examine and display their

experimental data. It may be downloaded free of charge from 

the website http://www.ncnr.nist.gov/dave/, either as a binary

executable with an embedded runtime license or as the complete 

source code. Recent work has focused on upgrading existing

capabilities and adding new tools that extend the analysis and

visualization functionalities. Windows and Linux are now 

supported on 64-bit hardware machines in order to better cope 

with very large datasets such as those generated at the Spallation

Neutron Source (Oak Ridge).

Education and Outreach

One of the missions of the CHRNS program is to contribute 

to the development of human resources through education and

outreach, thereby fostering future generations of scientists and 

neutron scatterers.

The Center for High Resolution Neutron Scattering (CHRNS)
NCNR 2009 Accomplishments and Opportunities 61

This was the 15th annual CHRNS sponsored neutron scattering 

summer school. The 2009 school, devoted to spectroscopy, 

attracted 90 applicants for the 35 available places. The CHRNS 

summer schools are very effective in educating potential new users 

of neutron scattering as more than 70 % of the participants return 

to the NCNR for their own research. Course materials have been 

placed on the Web.

We also offered a series of tutorial demonstrations based on the 

experiments and lectures presented at the 2008 Summer School 

on Small Angle Neutron Scattering and Reflectometry. Fifty-one 

participants, from US universities and from twenty-one NIST 

divisions other than the NCNR, attended the tutorials. Course 

materials will be placed on the Web.

FIGURE 2: The 2009 SURF students

CHRNS once again participated in NIST’s Summer 

Undergraduate Research Fellowship (SURF) program, hosting 

nine undergraduate students who worked with staff members 

studying materials that included hydrogen storage systems, 

magnetic nanoparticle films for data storage applications, and 

disordered protein structures. The students enthusiastically 

agreed that their summer research experiences were productive 

and worthwhile, and their advisors benefited from their efforts, 

expanding their understanding of the scientific process. 

2009 was the third year that 

NIST organized a “Summer 

Institute” for middle 

school science teachers. 

Eighteen teachers from 

three Maryland counties 

participated this year. 

They toured the NCNR 

and attended lectures 

and demonstrations that 

described how neutrons 

are used to probe matter. 

They were also provided the 

opportunity to interact with 

facility users, SURF students and the scientific staff. The neutron 

scattering component of the Summer Institute gave teachers a 

greater appreciation of what can be accomplished using neutron 

scattering.

FIGURE 3: Middle school science teachers and NCNR/CHRNS staff

This was the second year that high school students worked on 

research projects with an NCNR staff member. Mr. Vikas Bhatia 

from Gaithersburg High School worked with his advisor 

Dr. Jasmine Millican on the synthesis and characterization of 

Yttrium Cerium Titanium Oxide. Mr. Pavan Bhargava and his 

advisor Dr. Joseph Dura worked on the production of novel 

Nafion thin films for the development of lipid bilayers. 

Other education and outreach activities included “Bring your 

Kids to Work Day”, and tours for middle school and high school 

students. During the “Bring your Kids to Work Day,” held every 

year in the month of April, NIST opens its doors to more than 

250 students ranging from 6th through 12th grades. Within this 

site-wide yearly program, NCNR prepares tours of the facility, 

lectures and demonstrations specially designed for middle school 

age children on how neutrons are used to probe matter. 

FIGURE 1: NCNR 2009 Summer School participants
62Awards 2009

Awards 2009

Craig Brown of the NCNR has been chosen 

to receive a Presidential Early Career Award

for Scientists and Engineers (PECASE) at the 

White House this year. The PECASE Awards 

are intended to recognize some of the finest

scientists and engineers who, while early in 

their research careers, show exceptional potential for leadership

at the frontiers of scientific knowledge during the twenty-first

century. Dr. Brown is being recognized for his pioneering work 

on hydrogen storage materials.

Michihiro Nagao, guest researcher at the

NCNR, will receive the 2009 Young Scientist 

Award of the Physical Society of Japan in

the area of Soft Matter Physics.  He is being 

recognized for his paper entitled “Concentration

dependence of shape and structure fluctuations

of droplet microemulsions investigated by neutron spin echo 

spectroscopy,” work carried out at NCNR’s Neutron Spin Echo

instrument where Dr. Nagao is an instrument scientist.

Richard Lindstrom, retired from NIST and

currently guest scientist with the Analytical

Chemistry Division at the NCNR has been 

selected to receive the Hevesy Medal Award 

2009 “for his exceptional and comprehensive

contributions to radioanalytical measurement 

science, namely prompt gamma-ray activation 

analysis and gamma-ray spectrometry, and for his educational and

organizational activities.” The George Hevesy Medal Award is the

premier international award of excellence in radioanalytical and

nuclear chemistry.

Sungdae Ji, postdoctoral appointee at the 

University of Virginia and guest researcher 

at the NCNR has been chosen for the 2008

Young Researcher Science Award from 

the Korean Synchrotron Radiation User’s

Association.

Susan T. Krueger of the NCNR was awarded

the DOC Bronze Medal “for research in the

basic biological science of viral protein structures.”

Paul A. Kienzle of the NCNR was awarded

the DOC Bronze Medal for “development of

the Reflpak software package” which has had

a major impact on the usefulness of neutron 

reflectometry research.

Dona M. Hanak, secretary at the NCNR, has been 

recognized with a NIST Eugene Casson Crittenden

Award for “her willingness to accept extra work and

perform new administrative assignments benefiting

the NCNR.”

NIST Standards Alumni Association Portrait Gallery

of Distinguished Alumni 2009 has added NCNR’s 

Tawfik Raby “for contributions to NIST and national

goals through his leadership of the Reactor Operations and

Engineering Group to create the most reliable and costeffective major research reactor in the world.”

Taner Yildirim has been appointed Fellow of the

American Physical Society. Yildirim’s citation reads:

“For combining analytic theory, first-principles computations,

and neutron scattering measurements to design, discover, and

understand new materials with novel physics.”

Dan Neumann of the NCNR has been appointed

Fellow of the American Physical Society. Neumann’s 

citation reads: “for seminal studies of the structure

and dynamics of new carbon-based materials and

critical leadership serving the U.S. neutron scattering

community.”

Jeff Nico of the Ionizing Radiation Division at the

NCNR has been appointed Fellow of the American

Physical Society. “In recognition of his contributions and

leadership in precision measurements and fundamental

symmetry tests using cold neutrons, and his contributions

to radiochemical determinations of the p-p fusion solar

neutrino flux.”

Jae-Hyuk Her of the NCNR was selected by the

NIST chapter of Sigma Xi for a 2009 outstanding 

poster award for his presentation: “Structural Studies

on Various Hydrogen Storage Materials: MIL-53, 

K2Zn3[Fe(CN)6]2 and Li2B12H12.”

Jason Simmons of the NCNR was selected by the

NIST chapter of Sigma Xi for a 2009 outstanding 

poster award for his presentation: “Nanoporous 

Carbons and Coordination Polymers for Energy-related

Applications: Alternative Fuels and Carbon Capture.”

Winnie K. Wong-Ng of the NIST Ceramics

Division was awarded a DOC Bronze Medal for 

leading a multiyear team “project resulting in accurate

phase diagrams for the entire class of high-temperature

superconducting ceramic materials.”
NCNR 2009 Accomplishments and Opportunities 63

Marcus T. Cicerone and 

Christopher L. Soles, both of 

the NIST Polymers Division, 

were awarded a DOC Bronze 

Medal for “the seminal discovery 

that nanosecond molecular 

dynamics are critical in determining” the “viability of freeze-dried 

biopharmaceuticals.” Several key experiments in this work were 

performed using inelastic scattering instruments at the NCNR.

Tiffany Santos of Argonne National Laboratory 

has been selected for a L’Oreal USA Fellowship 

for Women in Science for her work in transition 

metal oxides at the Center for Nanoscale Materials at 

Argonne. Awardees each receive $60,000 grants to be 

used toward independent scientific research and career 

development. Her plans include the use of NCNR 

neutron facilities to pursue her oxide work, and also to support an 

undergraduate student through the course of a short-term research 

project under her guidance.

Prof. Frank Bates of the University of Minnesota 

is part of a team of five researchers that was chosen 

for the 2008 Cooperative Research Award in 

Polymer Science and Engineering “for their highly 

productive and sustained collaborative efforts in the 

area of poly(cyclohexylene) block copolymers.” The 

UM shares a PRT operating the NG-7 SANS instrument where many 

of Prof. Bates’ experiments were carried out.

Prof. Steven White of the University of California 

at Irvine was selected for the Avanti Award in 

Lipids by the Biophysical Society “for his novel 

findings in the areas of membrane structure and 

protein insertion into membranes.” Prof. White 

and his group have conducted their reflectometry 

measurements at the NCNR’s AND/R instrument.

Prof. Valery Kiryukhin of Rutgers University was 

selected for a Friedrich Wilhelm Bessel Research 

Award from the Alexander von Humboldt 

Foundation in Germany. Award winners are 

honored “for their outstanding research record and 

invited to spend a period of up to one year cooperating 

on a long-term research project with specialist colleages 

at a research institution in Germany.” Prof. Kiryukhin recently spent 

sabbatical time at the NCNR, performing measurements at the BT-9 

spectrometer.

Prof. Jeffrey Thomas of Northwestern University 

was selected for the 2008 Brunauer Award by the 

American Ceramic Society for his paper “A New 

Approach to Modeling the Nucleation and Growth 

Kinetics of Tricalcium Silicate Hydration.” Prof. 

Thomas’s group uses SANS and inelastic scattering 

instruments at the NCNR.

Susan Fullerton Shirey, recent doctoral recipient 

from Prof. Janna Maranas group at Penn State 

University, was selected to receive the 2009 

Frank J. Padden, Jr. Award from the American 

Physical Society for “excellence in polymer physics 

research.” Her work appears as a highlight in this 

issue on pp. 32–33.

Jinsheng Wen, a graduate student at University 

of Stony Brook working at Brookhaven National 

Laboratory, was chosen for a Margaret C. Etter 

Student Lecturer Award at the 2009 Annual Meeting 

of the American Crystallographic Association. The 

neutron measurements in his paper “Magnetic Field 

Effect on Charge Order in the New Multiferroic LuFe2O4”

were made at the NCNR.

Monica Branco, recent doctoral student at the 

University of Delaware, was invited to speak at 

the 2009 American Chemical Society meeting 

in recognition of her Excellence in Graduate 

Polymer Research. Her paper was entitled 

“Neutron scattering analysis of the dynamics and 

structure of semiflexible, self-assembled peptide chain networks.” Her 

work appears as a highlight in this issue on pp. 42–43.

Prof. James Eckert of Harvey Mudd College 

was the recipient of the 2009 Prize for a Faculty 

Member for Research in an Undergraduate 

Institution awarded by the American Physical 

Society. “For the significant contributions he has 

made to the understanding of the complex exchange 

biasing mechanism crucial to spin-valve sensors used 

in the read-write heads of hard disks and for his skilled and enthusiastic 

inclusion of undergraduates in physics research.” Prof. Eckert’s student, 

Stephanie Moyerman, an APS Apker award winner in 2006, 

conducted neutron reflectometry work at the NCNR.
64

Publications: August 1, 2008 to July 31, 2009

Acosta, E.J., Szekeres, E., Harwell, J.H., Grady, B.P., Sabatini, 

D.A., “Morphology of Ionic Microemulsions: Comparison 

of SANS Studies and the Net-Average Curvature (NAC)

Model,” Soft Matter 5 (3), 551 (2009).

Akcora, P., Liu, H., Kumar, S.K., Moll, J., Li, Y., Benicewicz, 

B.C., Schadler, L.S., Acehan, D., Panagiotopoulos, A.Z., 

Pryamitsyn, V., Ganesan, V., Ilavsky, J., Thiyagarajan, P.,

Colby, R.H., Douglas, J.F., “Anisotropic Self-Assembly of 

Spherical Polymer-Grafted Nanoparticles,” Nat. Mater. 8 (4),

354 (2009).

Akgun, B., Uğur, G., Jiang, Z., Narayanan, S., Song, S., Lee, H.,

Brittain, W.J., Kim, H., Sinha, S.K., Foster, M.D., “Surface 

Dynamics of ‘Dry’ Homopolymer Brushes,” Macromol. 42

(3), 737 (2009).

Alinger, M.J., Odette, G.R., Hoelzer, D.T., “On the Role of Alloy

Composition and Processing Parameters in Nanocluster

Formation and Dispersion Strengthening in Nanostuctured

Ferritic Alloys,” Acta Mater. 57 (2), 392 (2009).

Allen, A.J., Hackley, V.A., Jemian, P.R., Ilavsky, J., Raitano, J.M., 

Chan, S.-W., “In Situ Ultra-Small-Angle X-Ray Scattering

Study of the Solution-Mediated Formation and Growth

of Nanocrystalline Ceria,” J. Appl. Crystallogr. 41 (5), 918 

(2008).

Alsmadi, A.M., Alyones, S., Mielke, C.H., McDonald, R.D.,

Zapf, V., Altarawneh, M.M., Lacerda, A., Chang, S., 

Adak, S., Kothapalli, K., Nakotte, H., “Radio-Frequency

Measurements of UNiX Compounds (X=Al, Ga, Ge) in 

High Magnetic Fields,” J. Mag. Mag. Mater., in press.

Amoretti, G., Caciuffo, R., Carretta, S., Guidi, T., Magnani, N.,

Santini, P., “Inelastic Neutron Scattering Investigations of

Molecular Nanomagnets,” Inorg. Chim. Acta 361 (14), 3771 

(2008). (CHRNS)

Anderson, D.L., “Analytical Capabilities of Anticoincidence

INAA for Biological Materials,” J. Radioanal. Nucl. Chem., 

in press.

Anderson, D.L., “Determination of Bromine in Regulated Foods

with a Field-Portable X-Ray Fluorescence Analyzer,” J. 

AOAC Int. 92 (2), 502 (2009).

Anderson, D.L., “Screening of Foods and Related Products for

Toxic Elements with a Portable X-Ray Tube Analyzer,” J. 

Radioanal. Nucl. Chem., in press.

Anderson, D.L., “Use of L-Cysteine for Minimization of Inorganic 

Hg Loss During Thermal Neutron Irradiation,” J. Radioanal.

Nucl. Chem., in press.

Araos, M.U., Warr, G.G., “Structure of Nonionic Surfactant Micelles in

the Ionic Liquid Ethylammonium Nitrate,” Langmuir 24 (17), 9354

(2008). (CHRNS)

Arif, M., Hussey, D.S., Jacobson, D.L., “Neutron Imaging for the 

Hydrogen Economy,” Neutron Imaging and Applications 11, 191

(2009).

Atakan, V., Chen, C.-W., Paul, R., Riman, R.E., “Quantification of 

Hydroxyl Content in Ceramic Oxides: A Prompt γ Activation

Analysis Study of BaTiO3,” Anal. Chem. 80 (17), 6626 (2008).

Bao, W., Gasparovic, Y.C., Lynn, J.W., Ronning, F., Bauer, E.D., 

Thompson, J.D., Fisk, Z., “Commensurate Magnetic Structure of

CeRhIn4.85Hg0.15,” Phys. Rev. B 79 (9), 092415 (2009).

Bao, W., Qiu, Y., Huang, Q., Green, M.A., Zajdel, P., Fitzsimmons, M.R., 

Zhernenkov, M., Chang, S., Fang, M., Qian, B., Vehstedt, E.K.,

Yang, J., Pham, H.M., Spinu, L., Mao, Z.Q., “Tunable (δπ, δπ)-Type

Antiferromagnetic Order in α-Fe(Te,Se) Superconductors,” Phys. 

Rev. Lett. 102 (24), 247001 (2009). (CHRNS)

Barker, J.G., Mildner, D.F.R., Rodriguez, J.A., Thiyagarajan, P., “Neutron 

Transmission of Single-Crystal Magnesium Fluoride,” J. Appl. 

Crystallogr. 41 (6), 1003 (2008). (CHRNS)

Belik, A.A., Huang, Q., Takayama-Muromachi, E., Lynn, J.W., “Neutron 

Powder Diffraction Study of the Magnetic and Crystal Structures of 

SrFe2(PO4)2,” J. Solid State Chem. 181 (9), 2292 (2008).

Berk, N.F., Majkrzak, C.F., “Analysis of Multibeam Data for Neutron 

Reflectivity,” Langmuir 25 (7), 4145 (2009).

Berk, N.F., Majkrzak, C.F., “Statistical Analysis of Phase-Inversion 

Neutron Specular Reflectivity,” Langmuir 25 (7), 4132 (2009).

Bianchi, A., Carretta, S., Santini, P., Amoretti, G., Guidi, T., Qiu, 

Y., Copley, J.R.D., Timco, G., Muryn, C., Winpenny, R.E.P., 

“Rotational Bands in Open Antiferromagnetic Rings: A Neutron 

Spectroscopy Study of Cr8Zn,” Phys. Rev. B 79 (14), 144422 (2009). 

(CHRNS)

Blackburn, E., Goodkind, J., Sinha, S.K., Broholm, C., Copley, J.R.D.,

Erwin, R., “Neutron Scattering Study of the Excitation Spectrum of 

Solid Helium at Ultra-Low Temperatures,” PRAMANA J. Phys. 71

(4), 673 (2008). (CHRNS)

Borup, R.L., Mukundan, R., Davey, J., Spendelowa, J., Hussey, D.S.,

Jacobson, D.L., and Arif, M., “In Situ PEM Fuel Cell Water 

Measurements,” ECS Trans. 17 (1), 263 (2008).

Branco, M.C., Nettesheim, F., Pochan, D.J., Schneider, J.P., Wagner, N.J., 

“Fast Dynamics of Semiflexible Chain Networks of Self-Assembled

Peptides,” Biomacromol. 10 (6), 1374 (2009). (CHRNS)

Publications
NCNR 2009 Accomplishments and Opportunities 65

Bridges, C.A., Krishnamurthy, V.V., Poulton, S., Paranthaman, M.P., Sales, 

B.C., Myers, C., Bobev, S., “Magnetic Order in CaMn2Sb2 Studied 

via Powder Neutron Diffraction,” J. Mag. Mag. Mater., in press.

Brown, C.M., Liu, Y., Neumann, D.A., “Neutron Powder Diffraction of 

Metal-Organic Frameworks for Hydrogen Storage,” PRAMANA J. 

Phys. 71 (4), 755 (2008).

Brown, C.M., Liu, Y., Yildirim, T., Peterson, V.K., Kepert, C.J., 

“Hydrogen Adsorption in HKUST-1: A Combined Inelastic 

Neutron Scattering and First-Principles Study,” Nanotech. 20 (20), 

204025 (2009). (CHRNS)

Bumrongjaroen, W., Livingston, R.A., Neumann, D.A., Allen, A.J., 

“Characterization of Fly Ash Reactivity in Hydrating Cement by 

Neutron Scattering,” J. Mater. Res. 24 (7), 2435 (2009). (CHRNS)

Cabrera, I., Kenzelmann, M., Lawes, G., Chen, Y., Chen, W.C., Erwin, 

R., Gentile, T.R., Leão, J.B., Lynn, J.W., Rogado, N., Cava, R.J., 

Broholm, C., “Coupled Magnetic and Ferroelectric Domains in 

Multiferroic Ni3V2O8,” Phys. Rev. Lett., in press.

Cai, J., Zhang, L., Liu, S., Liu, Y., Xu, X., Chen, X., Chu, B., Guo, X., 

Xu, J., Cheng, H., Han, C.C., Kuga, S., “Dynamic Self-Assembly 

Induced Rapid Dissolution of Cellulose at Low Temperatures,” 

Macromol. 41 (23), 9345 (2008).

Cao, H., Bai, F., Li, J., Viehland, D., Lograsso, T.A., Gehring, P.M., 

“Structural Studies of Decomposition in Fe-x at.%Ga Alloys,” J. 

Alloys Compd. 465 (1), 244 (2008).

Cao, H., Gehring, P.M., Devreugd, C.P., Rodriguez-Rivera, J.A., Li, J., 

Viehland, D., “Role of Nanoscale Precipitates on the Enhanced 

Magnetostriction of Heat-Treated Galfenol (Fe1-xGax) Alloys,” Phys. 

Rev. Lett. 102 (12), 127201 (2009).

Cao, H., Stock, C., Xu, G., Gehring, P.M., Li, J., Viehland, D., “Dynamic 

Origin of the Morphotropic Phase Boundary: Soft Modes and Phase 

Instability in 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3,” Phys. Rev. B 78

(10), 104103 (2008).

Cao, L., Bindel, R., “The Use of Webcam for Neutron Imaging,” Trans. 

Am. Nucl. Soc. 100, 243 (2009).

Cao, L.R., Hattrick-Simpers, J.R., Bindel, R., Tomlin, B.E., Zeisler, R., 

Paul, R., Bendersky, L.A., Downing, R.G., “Combinatorial Study of 

Thin Film Metal Hydride by Prompt Gamma Activation Analysis,” J. 

Radioanal. Nucl. Chem., in press.

Cao, L.R., Hattrick-Simpers, Oguchi, H., Paul, R., Bendersky, L., 

Downing, R.G., “The Study of Thin Film Metal Hydride with 

Prompt Gamma Activation Analysis,” Trans. Am. Nucl. Soc. 99, 268 

(2008).

Cappelletti, R.L., editor, “2008 NIST Center for Neutron Research 

Accomplishments and Opportunities,” NIST SP 1089 (2008).

Cetinkol, M., Wilkinson, A.P., Lee, P.L., “Structural Changes 

Accompanying Negative Thermal Expansion in Zr2(MoO4)(PO4)2,” 

J. Solid State Chem. 182 (6), 1304 (2009).

Chatjaroenporn, K., Baker, R.W., FitzGerald, P.A., Warr, G.G., “Structure 

Changes in Micelles and Adsorbed Layers During Surfactant 

Polymerization,” J. Colloid Inter. Sci. 336 (2), 449 (2009).

Chaudhury, R.P., Lorenz, B., Wang, Y.Q., Sun, Y.Y., Chu, C.W., Ye, F., 

Fernandez-Baca, J., Mook, H., Lynn, J., “Re-Entrant Spiral Magnetic 

Order and Ferroelectricity in Mn1-xFexWO4 (x=0.035),” J. Appl. 

Phys. 105 (7), 07D913 (2009).

Chen, C., Maranas, J.K., “A Molecular View of Dynamic Responses When 

Mixing Poly(Ethylene Oxide) and Poly (Methyl Methacrylate),” 

Macromol. 42 (7), 2795 (2009). (CHRNS)

Chen, H., Ren, Y., Qiu, Y., Bao, W., Liu, R.H., Wu, G., Wu. T., Xie, Y.L., 

Wang, X.F., Huang, Q., Chen, X.H., “Coexistence of the SpinDensity-Wave and Superconductivity in the Ba1-xKxFe2As2,” EPL 85

(1), 17006 (2009).

Chen, J.-H., Chang, C.-S., Chang, Y.-X., Chen, C.-Y., Chen, H.-L., Chen, 

S.-A., “Gelation and Its Effect on the Photophysical Behavior of 

Poly(9,9-dioctylfluorene-2,7-diyl) in Toluene,” Macromol. 42 (4), 

1306 (2009). (CHRNS)

Chen, S.-H., Zhang, Y., Lagi, M., Chong, S.-H., Baglioni, P., Mallamace, 

F., “Evidence of Dynamic Crossover Phenomena in Water and Other 

Glass-Forming Liquids: Experiments, MD Simulations and Theory,” 

J. Phys.: Condens. Mat., in press.

Chen, S.-H., Zhang, Y., Lagi, M., Chu, X., Liu, L., Faraone, A., Fratini, E., 

Baglioni, P., “The Dynamic Response Function χT(Q,t) of Confined 

Supercooled Water and its Relation to the Dynamic Crossover 

Phenomenon,” Z. Phys. Chem., in press. (CHRNS)

Chen, W.C., Erwin, R., McIver III, J.W., Watson, S., Fu, C.B., Gentile, 

T.R., Borchers, J.A., Lynn, J.W., Jones, G.L., “Applications of 3

He 

Neutron Spin Filters at the NCNR,” Physica B, in press. (CHRNS)

Chen, Y., Lynn, J.W., Li, J., Li, G., Chen, G.F., Luo, J.L., Wang, N.L., Dai, 

P., dela Cruz, C., Mook, H.A., “Magnetic Order of the Iron Spins in 

NdFeAsO,” Phys. Rev. B 78 (6), 064515 (2008).

Chen, Y., Ueland, B.G., Lynn, J.W., Bychkov, G.L., Barilo, S.N., 

Mukovskii, Y.M., “Polaron Formation in the Optimally Doped 

Ferromagnetic Manganites La0.7Sr0.3MnO3 and La0.7Ba0.3MnO3,” 

Phys. Rev. B 78 (21), 212301 (2008).

Cheng, G., Graessley, W.W., Melchenko, Y.B., “Polymer Dimensions 

in Good Solvents: Crossover from Semidilute to Concentrated 

Solutions,” Phys. Rev. Lett. 102 (15), 157801 (2009). (CHRNS)

Cheng, G., Melnichenko, Y.B., Wignall, G.D., Hua, F., Hong, K., Mays, 

J.W., “Small Angle Neutron Scattering Study of Conformation of 

Oligo(Ethylene Glycol)-Grafted Polystyrene in Dilute Solutions: 

Effect of the Backbone Length,” Macromol. 41 (24), 9831 (2008). 

(CHRNS)

Chi, S., Adroja, D.T., Guidi, T., Bewley, R., Li, S., Zhao, J., Lynn, 

J.W., Brown, C.M., Qiu, Y., Chen, G.F., Lou, J.L., Wang, N.L., 

Dai, P., “Crystalline Electric Field as a Probe for Long-Range 

Antiferromagnetic Order and Superconducting State of 

CeFeAsO1-xFx,” Phys. Rev. Lett. 101 (21), 217002 (2008). (CHRNS)
66

Cho, J.Y., Millican, J.N., Capan, C., Sokolov, D.A., Moldovan, 

M., Karki, A.B., Young, D.P., Aronson, M.C., Chan, J.Y., 

“Crystal Growth, Structure, and Physical Properties of 

Ln2MGa12 (Ln = La, Ce; M = Ni, Cu),” Chem. Mater. 20

(19), 6116 (2008).

Chokshi, U., Selvam, P., Porcar, L., da Rocha, S.R.P., “Reverse

Aqueous Emulsions and Microemulsions in HFA227

Propellant Stabilized by Non-Ionic Ethoxylated 

Amphiphiles,” Int. J. Pharm. 369 (1-2), 176 (2009). (CHRNS)

Christensen, M., Abrahamsen, A.B., Christensen, N.B., Juranyi, 

F., Andersen, N.H., Lefmann, K., Andreasson, J., Bahl,

C.R.H., Iversen, B.B., “Avoided Crossing of Rattler Modes in

Thermoelectric Materials,” Nat. Mater. 7, 811 (2008).

Chu, X.-Q., Faraone, A., Kim, C., Fratini, E., Baglioni, P.,

Leao, J.B., Chen, S.-H., “Proteins Remain Soft at Lower

Temperatures under Pressure,” J. Phys. Chem. B 113 (15),

5001 (2009). (CHRNS)

Chung, J.-H., Chung, S.J., Lee, S., Kirby, B.J., Borchers, J.A.,

Cho, Y.J., Liu, X., Furdyna, J.K., “Carrier-Mediated

Antiferromagnetic Interlayer Exchange Coupling in

Diluted Magnetic Semiconductor Multilayers Ga1-xMnxAs/

GaAs:Be,” Phys. Rev. Lett. 101 (23), 237202 (2008).

Chung, J.-H., Lim, J.-H., Shin, J., Kang, J.-S., Jaiswal-Nagar, 

D., Kim, K.H., “Possible Charge Disproportionation in 

3R-AgNiO2 Studied by Neutron Powder Diffraction,” Phys.

Rev. B 78 (21), 214417 (2008).

Clancy, J.P., Ruff, J.P.C., Dunsiger, S.R., Zhao, Y., Dabkowska,

H.A., Gardner, J.S., Qiu, Y., Copley, J.R.D., Jenkins, T.,

Gaulin, B.D., “Revisiting Static and Dynamic Spin-Ice 

Correlations in Ho2Ti2O7 with Neutron Scattering,” Phys. 

Rev. B 79 (1), 014408 (2009). (CHRNS)

Clerici, C., Gu, X., Sung, L., Forster, A.M., Ho, D.L., Stutzman, 

P., Nguyen, T., Martin, J.W., “Effect of Pigment Dispersion 

on Durability of a TiO2 Pigmented Epoxy Coating

During Outdoor Exposure,” in “Service Life Prediction for

Polymeric Materials: Global Perspectives,” edited by Martin, 

J.W., Ryntz, R.A., Chin, J., and Dickie, R., (Springer US) 

Chap. 31, 475 (2009).

Cleveland IV, T.E., Hussey, D.S., Chen, Z.-Y., Jacobson, D.L.,

Brown, R.L., Carter-Wientjes, C., Cleveland, T.E., Arif,

M., “The Use of Neutron Tomography for the Structural 

Analysis of Corn Kernels,” J. Cereal Sci. 48, 517 (2008).

Cole, D.R., Mamontov, E., Rother, G., “Structure and Dynamics 

of Fluids in Microporous and Mesoporous Earth and 

Engineered Materials,” in “Neutron Applications in Earth,

Energy and Environmental Sciences,” edited by Liang, 

L., Rinaldi, R., Schober, H., (Springer US) Chap. 19, 547

(2009). (CHRNS)

Comoletti, D., Grishaev, A., Whitten, A.E., Taylor, P., Trewhella, J.,

“Characterization of the Solution Structure of a Neuroligin/βNeurexin Complex,” Chem. Biol. Interact. 175 (1-3), 150 (2008).

Contescu, C.I., Bhat, V.V., Gallego, N.C., “Hydrogen Spillover: Its

‘Diffusion’ From Catalysis to Hydrogen Storage Community,” ACS 

Div. Fuel Chem. 54 (1), 382 (2009).

Contescu, C.I., Brown, C.M., Liu, Y., Bhat, V.V., Gallego, N.C., 

“Detection of Hydrogen Spillover in Palladium-Modified Activated

Carbon Fibers During Hydrogen Adsorption,” J. Phys. Chem. C 

113 (14), 5886 (2009).

Cook, J.C., “Design and Estimated Performance of a New Neutron Guide

System for the NCNR Expansion Project,” Rev. Sci. Instrum. 80 (3), 

023101 (2009).

Cooper, J.W., Coplan, M.A., Hughes, P.P., “The Detection of Lyman

Alpha Radiation Formed by the Slowing Down of Protons and

Tritons Produced by the He-3 (n,tp) Reaction - A Model Study,” J. 

Res. Natl. Inst. Stand. Technol. 114 (3), 185 (2009).

Copley, J.R.D., Brown, C.M., Qiu, Y., “Time-of-Flight Spectroscopy at

the NIST Center for Neutron Research,” Neutron News 20 (2), 28

(2009). (CHRNS)

Cui, H., Muraoka, T., Cheetham, A., Stupp, S.I., “Self-Assembly of Giant

Peptide Nanobelts,” Nano Lett. 9 (3), 945 (2009). (CHRNS)

Dai, P., Wilson, S.D., Li, S., Wen, H.-H., “Nature of the Quantum

Spin Correlations Through the Superconducting-Normal Phase

Transition in Electron-Doped Superconducting Pr0.88LaCe0.12CuO4,” 

J. Phys. Chem. Solids 69 (12), 3096 (2008).

Dandu, R., Von Cresce, A., Briber, R., Dowell, P., Cappello, J., 

Ghandehari, H., “Silk–Elastinlike Protein Polymer Hydrogels: 

Influence of Monomer Sequence on Physicochemical Properties,” 

Polymer 50 (2), 366 (2009).

Davey, J., Mukundan, R., Spendelow, J., Hussey, D.S., Jacobson, D., Arif,

M., Borup, R.L., “Water Dynamics in a PEM Fuel Cell: Effect of

Current and Humidity Transients,” ECS Trans. 16 (2), 329 (2008).

Doe, C., Choi, S.-M., Kline, S.R., Jang, H.-S., Kim, T.-H., “Charged

Rod-Like Nanoparticle Assisted Single-Wall Carbon Nanotube 

Dispersion in Water,” Adv. Func. Mater. 18, 2685 (2008). (CHRNS)

Doe, C., Jang, H.-S., Kline, S.R., Choi, S.-M., “Subdomain Structures 

of Lamellar and Reverse Hexagonal Pluronic Ternary Systems

Investigated by Small Angle Neutron Scattering,” Macromol. 42 (7),

2645 (2009).

Dowling, M.B., Lee, J.-H., Raghavan, S.R., “pH-Responsive Jello: Gelatin 

Gels Containing Fatty Acid Vesicles,” Langmuir, in press.

Dunsiger, S.R., Zhao, Y., Gaulin, B.D., Qiu, Y., Bourges, P., Sidis, Y.,

Copley, J.R.D., Kallin, A., Mazurek, E.M., Dabkowska, H.A., 

“Diagonal and Collinear Incommensurate Spin Structures in 

Underdoped La2−xBaxCuO4,” Phys. Rev. B 78 (9), 092507 (2008). 

(CHRNS)

Publications
NCNR 2009 Accomplishments and Opportunities 67

Dura, J.A., LaRock, J., “A Molecular Beam Epitaxy Facility for In Situ

Neutron Scattering,” Rev. Sci. Instrum. 80 (7), 073906 (2009).

Dura, J.A., Murthi, V.S., Hartman, M., Satija, S.K., Majkrzak, C.F., 

“Multilamellar Interface Structures in Nafion,” Macromol. 42 (13), 

4769 (2009).

Ehlers, G., Mamontov, E., Zamponi, M., Kam, K.C., Gardner, J.S., “Direct 

Observation of a Nuclear Spin Excitation in Ho2Ti2O7,” Phys. Rev. 

Lett. 102 (1), 016405 (2009).

ElMassalami, M., Rapp, R.E., Chaves, F.A.B., Moreno, R., Takeya, H., 

Ouladdiaf, B., Lynn, J.W., Huang, Q., Freitas, R.S., Oliveria Jr., N.F., 

“Synthesis and Magnetic Characterization of TmCo2B2C,” J. Phys.: 

Condens. Mat. 21 (4), 046007 (2009).

Emery, S.B., Wells, B.O., “Properties of Phase-Separated, SuperOxygenated La2−xSrxCuO4+y,” J. Supercond. Nov. Magn. 22 (1), 33 

(2009).

Faraone, A., Fratini, E., Todea, A.M., Krebs, B., Müller, A., Baglioni, P., 

“Dynamics of Water in Voids Between Well-Defined and Densely 

Packed Spherical Nanocages Acting as Polyprotic Inorganic Acids,” 

J. Phys. Chem. C 113 (20), 8635 (2009). (CHRNS)

Faraone, A., Liu, K.-H., Mou, C.-Y., Zhang, Y., Chen, S.-H., “Single 

Particle Dynamics of Water Confined in a Hydrophobically 

Modified MCM-41-S Nanoporous Matrix,” J. Chem. Phys. 130

(13), 134512 (2009). (CHRNS)

Ferguson, M.L., Prasad, K., Boukari, H., Sackett, D.L., Krueger, S., Lafer, 

E.M., Nossal, R., “Clathrin Triskelia Show Evidence of Molecular 

Flexibility,” Biophys. J. 95 (4), 1945 (2008). (CHRNS)

Fischbach, E., Buncher, J.B., Jenkins, J.H., Krause, D.E., Lindstrom, R.M., 

Mattes, J.J., “Possibility of a Self-induced Contribution to Nuclear 

Decays,” Trans. Am. Nucl. Soc. 100, 223 (2009).

Foster, B., Cosgrove, T., Hammouda, B., “Pluronic Triblock Copolymer 

Systems and Their Interactions with Ibuprofen,” Langmuir 25 (12), 

6760 (2009).

Frounfelker, B.D., Kalur, G.C., Cipriano, B.H., Danino, D., Raghavan, 

S.R., “Persistence of Birefringence in Sheared Solutions of Wormlike 

Micelles,” Langmuir 25 (1), 167 (2009). (CHRNS)

Fullerton-Shirey, S.K., Maranas, J.K., “Effect of LiClO4 on the Structure 

and Mobility of PEO-Based Solid Polymer Electrolytes,” Macromol. 

42 (6), 2142 (2009). (CHRNS)

Gagliardo, J.J., Owejan, J.P., Trabold, T.A., Tighe, T.W., “Neutron 

Radiography Characterization of an Operating Proton Exchange 

Membrane Fuel Cell with Localized Current Distribution 

Measurements,” Nucl. Instr. Meth. A 605 (1), 115 (2009).

Garcia Sakai, V., Mamontov, E., Neumann, D., “A Background 

Suppression Chopper for the High-Flux Backscattering 

Spectrometer at NIST,” J. Neutron Res., in press. (CHRNS)

Gasser, U., Sierra-Martin, B., Fernandez-Nieves, A., “Crystal Structure 

of Highly Concentrated, Ionic Microgel Suspensions Studied by 

Neutron Scattering,” Phys. Rev. E 79 (5), 051403 (2009).

Gawrisch, K., Soubias, O., Mihailescu, M., “Insights From Biophysical 

Studies on the Role of Polyunsaturated Fatty Acids for Function 

of G-Protein Coupled Membrane Receptors,” Prost. Leuk. Essent. 

Fatty Acids 79 (3), 131 (2008).

Gehring, P.M., Hiraka, H., Stock, C., Lee, S.-H., Chen, W., Ye, Z.-G., 

Vakhrushev, S.B., Chowdhuri, Z., “Reassessment of the Burns 

Temperature and its Relationship to the Diffuse Scattering, Lattice 

Dynamics, and Thermal Expansion in Relaxor Pb(Mg1/3Nb2/3)O3,” 

Phys. Rev. B 79 (22), 224109 (2009). (CHRNS)

Giblin, S.R., Champion, J.D.M., Zhou, H.D., Wiebe, C.R., Gardner, J.S., 

Terry, I., Calder, S., Fennell, T., Bramwell, S.T., “Static Magnetic 

Order in Tb2Sn2O7 Revealed by Muon Spin Relaxation with 

Exterior Muon Implantation,” Phys. Rev. Lett. 101 (23), 237201 

(2008).

Gnäupel-Herold, T., “Techniques for Neutron Stress Determination with 

High Spatial Resolution,” J. Nondestructive Evaluation, in press.

Gnäupel-Herold, T., Iadicola, M.A., Foecke, T., “Residual Stresses in 

Numisheet Benchmark 3 Panels,” in “Material Property Data for 

More Effective Numerical Analysis,” edited by Levy, B.S., Matlock, 

D.K., Van Tyne, C.J., (IDDRG Conf. Proc.) 7 (2009).

Gnäupel-Herold, T., “Formalism for the Determination of Intermediate 

Stress Gradients Using X-Ray Diffraction,” J. Appl. Crystallogr. 42

(2), 192 (2009).

Gogotsi, Y., Portet, C., Osswald, S., Simmons, J.M., Yildirim, T., Laudisio, 

G., Fischer, J.E., “Importance of Pore Size in High-Pressure 

Hydrogen Storage by Porous Carbons,” Int. J. Hydrogen Energy, in 

press.

Goldman, A.I., Kreyssig, A., Prokeš, K., Pratt, D.K., Argyriou, D.N., 

Lynn, J.W., Nandi, S., Kimber, S.A.J., Chen, Y., Lee, Y.B., Samolyuk, 

G., Leão, J.B., Poulton, S.J., Bud’ko, S.L., Ni, N., Canfield, P.C., 

Harmon, B.N., McQueeney, R.J., “Lattice Collapse and Quenching 

of Magnetism in CaFe2As2 Under Pressure: A Single-Crystal 

Neutron and X-Ray Diffraction Investigation,” Phys. Rev. B 79 (2), 

024513 (2009).

Green, M.A., “When Small is Better,” Nature 8, 450 (2009).

Guidi, T., Carretta, S., Santini, P., Amoretti, G., Caciuffo, R., Hiess, A., 

Copley, J.R.D., Qiu, Y., Timco, G., Winpenny, R.E.P., “Quantum 

Oscillations of the Total Spin in a Heterometallic Antiferromagnetic 

Ring,” Not. Neutroni Luce Sinc. 13 (2), 4 (2008). (CHRNS)

Gupta, S., Muralikiran, M., Farmer, J., Cao, L.R., and Downing, R.G., 

“The Effect of Boron Doping and Gamma Irradiation on the 

Structure and Properties of Microwave Chemical Vapor Deposited 

Boron-Doped Diamond Films,” J. Mater. Res. 24 (4), 1498 (2009).
68

Hamill, A.C., Lee Jr, C.T., “Photocontrol of β-Amyloid Peptide

(1−40) Fibril Growth in the Presence of a Photosurfactant,” 

J. Phys. Chem. B 113 (17), 6164 (2009). (CHRNS)

Han, X., Hristova, K., “Viewing the Bilayer Hydrocarbon Core 

Using Neutron Diffraction,” J. Memb. Biol. 227, 123 (2009).

Hanley, H.J.M., Payne, T.E., “Adsorption of a Jet Fuel on a Model 

Organic-Clay Soil: Application of Small Angle Neutron 

Scattering,” Can. J. Chem. Eng. 36 (3), 559 (2009).

Hansen, F.Y., Taub, H., “Decomposition of Molecular Motions 

Into Translational, Rotational, and Intramolecular Parts by 

a Projection Operator Techniques,” Comm. Comp. Phys., in

press.

Hassan, P.A., Hodgdon, T.K., Sagasaki, M., FritzPopovski, G., and Kaler, E.W., “Phase Behavior and

Microstructure Evolution in Aqueous Mixtures of

Cetyltrimethylammonium Bromide and Sodium Dodecyl

Tri-Oxyethylene Sulfate,” Comptes Rendus Chimie 12 (1), 

18 (2009).

Heinrich, F., Ng, T., Vanderah, D.J., Shekhar, P., Mihailescu, M., 

Nanda, H., Lösche, M., “A New Lipid Anchor for Sparsely

Tethered Bilayer Lipid Membranes,” Langmuir 25 (7), 4219 

(2009).

Heitfeld, K.A., Schaefer, D.W., “Structure-Property Relationships

in Flavour-Barrier Membranes with Reduced HighTemperature Diffusivity,” Soft Matter 5 (1), 156 (2009).

(CHRNS)

Helgeson, M.E., Vasquez, P.A., Kaler, E.W., Wagner, N.J., 

“Rheology and Spatially Resolved Structure of

Cetyltrimethylammonium Bromide Wormlike Micelles 

Through the Shear Banding Transition,” J. Rheol. 53 (3), 727

(2009). (CHRNS)

Her, J.-H., Kennon, B.S., Shum, W.W., Stephens, P.W., Miller, J.S., 

“Structure and Magnetic Properties of LnIII[Ru2(CO3)4>r

8H2O,” Inorg. Chim. Acta 361 (12-13), 3462 (2008).

Her, J.-H., Stephens, P.W., Ribas-Ariño, J., Novoa, J.J., Shum,

W.W., Miller, J.S., “Structure and Magnetic Interactions in

the Organic-Based Ferromagnet Decamethylferrocenium

Tetracyanoethenide, [FeCp*2]r[TCNE]r,” Inorg. Chem. 48

(8), 3296 (2009).

Her, J.-H., Yousufuddin, M., Zhou, W., Jalisatgi, S.S., Kulleck, 

J.G., Zan, J.A., Hwang, S.-J., Bowman Jr., R.C., Udovic, T.J.,

“Crystal Structure of Li2B12H12: A Possible Intermediate 

Species in the Decomposition of LiBH4,” Inorg. Chem. 47

(21), 9757 (2008).

Her, J.-H., Zhou, W., Stavila, V., Brown, C.M., Udovic, T.J., “Role 

of Cation Size on the Structural Behavior of the AlkaliMetal Dodecahydro-closo-Dodecaborates,” J. Phys. Chem. C

113 (16), 11187 (2009).

Hernández, Y., Brown, C.M., “User Facilities: The Education of New

Neutron Users,” in “8th International Conference on Methods and

Applications of Radioanalytical Chemistry: MARC-VIII,” edited 

by Zeisler, R., Ünlü, K., Heller-Zeisler, S., (AIP Conf. Proc.), in

press.

Heuser, B.J., Udovic, T.J., Ju, H., “Vibrational Density of States

Measurement of Hydrogen Trapped at Dislocations in Deformed

PdH0.0008,” Phys. Rev. B 78 (21), 214101 (2008).

Hodges, C.S., Biggs, S., Walker, L., “Complex Adsorption Behavior of

Rodlike Polyelectrolyte−Surfactant Aggregates,” Langmuir 25 (8),

4484 (2009).

Holt, S.A., Le Brun, A.P., Majkrzak, C.F., McGillivray, D.J., Heinrich, 

F., Lösche, M., Lakey, J.H., “An Ion-Channel-Containing Model

Membrane: Structural Determination by Magnetic Contrast 

Neutron Reflectometry,” Soft Matter 5 (13), 2567 (2009).

Hong, T., Garlea, V.O., Zheludev, A., Fernandez-Baca, J.A., Manaka,

H., Chang, S., Leao, J.B., Poulton, S.J., “Effect of Pressure on the

Quantum Spin Ladder Material IPA-CuCl3,” Phys. Rev. B 78 (22), 

224409 (2008). (CHRNS)

Horkay, F., “Biopolymer Gels: Nanostructure and Macroscopic 

Properties,” Prog. Colloid Polym. Sci. 135, 10 (2008). (CHRNS)

Horkay, F., Basser, P.J., “Ionic and pH Effects on the Osmotic Properties

and Structure of Polyelectrolyte Gels,” J. Polym. Sci., Part B: Polym.

Phys. 46 (24), 2803 (2008). (CHRNS)

Horkey, F., Basser, P.J., “Ion Sensitivity of DNA Gel Structure,” Polym.

Prepr. 49 (1), 438 (2008).

Hsieh, D., Qian, D., Berger, R.F., Cava, R.J., Lynn, J.W., Huang, Q., 

Hasan, M.Z., “Magnetic Excitations in Triangular Lattice NaCrO2,” 

J. Phys. Chem. Solids 69 (12), 3174 (2008).

Huang, E.-W., Liaw, P.K., Porcar, L., Liu, Y., Liu, Y.-L., Kai, J.-J., Chen, 

W.-R., “Study of Nanoprecipitates in a Nickel-Based Superalloy 

Using Small-Angle Neutron Scattering and Transmission Electron 

Microscopy,” Appl. Phys. Lett. 93 (16), 161904 (2008).

Huang, Q., Qiu, Y., Bao, W., Green, M.A., Lynn, J.W., Gasparovic,

Y.C., Wu, T., Wu, G., Chen, X.H., “Neutron-Diffraction

Measurements of Magnetic Order and a Structural Transition in

the Parent BaFe2As2 Compound of FeAs-Based High-Temperature 

Superconductors,” Phys. Rev. Lett. 101 (25), 257003 (2008).

Huang, Q., Zhao, J., Lynn, J.W., Chen, G.F., Lou, J.L., Wang, N.L., Dai, 

P., “Doping Evolution of Antiferromagnetic Order and Structural

Distortion in LaFeAsO1-xFx,” Phys. Rev. B 78 (5), 054529 (2008).

Hubbard Jr., F.P., Abbott, N.L., “A Small Angle Neutron Scattering Study 

of the Thicknesses of Vesicle Bilayers Formed from Mixtures of

Alkyl Sulfates and Cationic Bolaform Surfactants,” Soft Matter 4

(11), 2225 (2008).

Publications
NCNR 2009 Accomplishments and Opportunities 69

Huber, M.G., Arif, M., Black, T.C., Chen, W.C., Gentile, T.R., 

Hussey, D.S., Pushin, D.A., Wietfeldt, F.E., Yang, L., “Precision 

Measurement of the n-3

He Incoherent Scattering Length Using 

Neutron Interferometry,” Phys. Rev. Lett. 102 (20), 200401 (2009).

Hudson, S.D., Hutter, J.L., Nieh, M.P., Pencer, J., “Characterization of 

Anisotropic Poly(Vinyl Alcohol) Hydrogel by Small- and UltraSmall-Angle Neutron Scattering,” J. Chem. Phys. 130 (3), 034903 

(2009). (CHRNS)

Hyett, G., Green, M.A., Parkin, I.P., “An Investigation of TitaniumVanadium Nitride Phase Space, Conducted Using Combinatorial 

Atmospheric Pressure CVD,” Chem. Vap. Deposition 14 (9), 309 

(2008).

Hyett, G., Green, M.A., Parkin, I.P., “Ultra-Violet Light Activated 

Photocatalysis in Thin Films of the Titanium Oxynitride, Ti3−

δO4N,” J. Photochem. Photobiol. A 203 (2), 199 (2009).

Ikedo, Y., Nozaki, H., Harada, M., Sugiyama, J., Sato, T.J., Matsuo, 

Y., Nishiyama, K., Lord, J.S., Qiu, Y., Copley, J.R.D., “Study of 

Hydrogen Diffusion in Superprotonic Ionic Conductors, MHxO4,

by μ+SR and QENS,” Nucl. Instr. Meth. A 600 (1), 316 (2009). 

(CHRNS)

Inderhees, S.E., Borchers, J.A., Green, K.S., Kim, M.S., Sun, K., Strycker, 

G.L., Aronson, M.C., “Manipulating the Magnetic Structure of Co 

Core/CoO Shell Nanoparticles: Implications for Controlling the 

Exchange Bias,” Phys. Rev. Lett. 101 (11), 117202 (2008).

Jackson, A.J., Li, P.X., Dong, C.C., Thomas, R.K., Penfold, J., “Structure 

of Partially Fluorinated Surfactant Monolayers at the Air - Water 

Interface,” Langmuir 25 (7), 3957 (2009).

Jacques, D.A., Langley, D.B., Jeffries, C.M., Cunningham, K.A., 

Burkholder, W.F., Guss, J.M., Trewhella, J., “Histidine Kinase 

Regulation by a Cyclophilin-Like Inhibitor,” J. Mol. Biol. 384, 422 

(2008). (CHRNS)

Janik, J.A., Zhou, H.D., Jo, Y.J., Balicas, L., MacDougall, G.J., Luke, G.M., 

Garrett, J.D., McClellan, K.J., Bauer, E.D., Sarrao, J.L., Qiu, Y., 

Copley, J.R.D., Yamani, Z., Buyers, J.L., Wiebe, C.R., “Itinerant Spin 

Excitations Near the Hidden Order Transition in URu2Si2,” J. Phys.: 

Condens. Mat. 21 (19), 192202 (2009). (CHRNS)

Jha, A.K., Hule, R.A., Jiao, T., Teller, S.S., Clifton, R.J., Duncan, 

R.L., Pochan, D.J., Jia, X., “Structural Analysis and Mechanical 

Characterization of Hyaluronic Acid-Based Doubly Cross-Linked 

Networks,” Macromol. 42 (2), 537 (2009). (CHRNS)

Ji, S., Lee, S.H., Broholm, C., Koo, T.Y., Ratcliff, W., Cheong, S.W., 

Zschack, P., “Spin-Lattice Order in Frustrated ZnCr2O4,” Phys. Rev. 

Lett. 103 (3), 037201 (2009).

Jiang, J., Li, C., Lombardi, J., Colby, R.H., Rigas, B., Rafailovich, M.H., 

Sokolov, J.C., “The Effect of Physiologically Relevant Additives on 

the Rheological Properties of Concentrated Pluronic Copolymer 

Gels,” Polymer 49 (16), 3561 (2008). (CHRNS)

Jo, Y.J., Lee, S., Choi, E.S., Yi, H.T., Ratcliff, W., Choi, Y.J., Kiryukhin, 

V., Cheong, S.W., Balicas, L., “3:1 Magnetization Plateau and 

Suppression of Ferroelectric Polarization in an Ising Chain 

Multiferroic,” Phys. Rev. B 79 (1), 012407 (2009).

Johnson, M.E., Malardier-Jugroot, C., Murarka, R.K., Head-Gordon, T., 

“Hydration Water Dynamics Near Biological Interfaces,” J. Phys. 

Chem. B 113 (13), 4082 (2009). (CHRNS)

Kadowaki, H., Motoya, K., Sato, T.J., Lynn, J.W., Fernandez-Baca, 

J.A., Kikuchi, J., “Quantum Phase Transition in the Itinerant 

Antiferromagnet (V0.9Ti0.1)2O3,” Phys. Rev. Lett. 101 (9), 096406 

(2008).

Kalman, D.P., Wagner, N.J., “Microstructure of Shear-Thickening 

Concentrated Suspensions Determined by Flow-USANS,” Rheol. 

Acta, in press. (CHRNS)

Kamazawa, K., Louca, D., Morinaga, R., Sato, T.J., Huang, Q., 

Copley, J.R.D., Qiu, Y., “Field-Induced Antiferromagnetism and 

Competition in the Metamagnetic State of Terbium Gallium 

Garnet,” Phys. Rev. B 78 (6), 064412 (2008). (CHRNS)

Kang, J., Shin, N., Jang, D.Y., Prabhu, V.M., Yoon, D.Y., “Structure and 

Properties of Small Molecule−Polymer Blend Semiconductors for 

Organic Thin Film Transistors,” J. Am. Chem. Soc. 130 (37), 12273 

(2008).

Kang, S., Prabhu, V.M., Soles, C.L., Lin, E.K., and Wu, W.-L., 

“Methodology for Quantitative Measurements of Multilayer 

Polymer Thin Films with IR Spectroscopic Ellipsometry,” 

Macromol. 42 (14) 5296 (2009).

Karul, A., Tan, K.T., White, C.C., Hunston, D.L., Marshall, S.T., 

Akgun, B., Satija, S.K., Soles, C.L., Vogt, B.D., “Impact of Polymer 

Modulus/Chain Mobility on Water Accumulation at Polymer/

Metal Oxide Interfaces,” Polymer 50 (14), 3234 (2009).

Keally, C., Sokolova, A., Kearley, G., Kemner, E., Russina, M., Faraone, 

A., Hamilton, W., Gilbert, E., “Dynamical Transition in a Large 

Globular Protein: Macroscopic Properties and Glass Transition,” 

Biochim. Biophys. Acta, in press. (CHRNS)

Kennon, B.S., Her, J.H,. Stephens, P.W., Miller, J.S., “Diruthenium 

Tetracarbonate Trianion, [RuII/III2(O2CO)4]3

−, Based MoleculeBased Magnets: Three-Dimensional Network Structure and 

Two-Dimensional Magnetic Ordering,” Inorg. Chem. 48 (13), 6117 

(2009).

Kent, M.S., Murton, J.K., Dibble, D.C., Zendejas, F., Banuelos, J.L., 

Urquidi, J., Hjelm, R., Simmons, B.A., “Effect of Agitation/Flow 

on the Enzymatic Digestion of Cellulose: A Structural Study by 

SANS,” ACS Chem. Biol., in press.

Kent, M.S., Murton, J.K., Zendejas, F.J., Tran, H., Simmons, B.A., Satija, 

S., Kuzmenko, I., “Nanosilica Formation at Lipid Membranes 

Induced by the Parent Sequence of a Silaffin Peptide,” Langmuir 25

(1), 301 (2009).
70

Kepa, H., Majkrzak, C.F., Sipatov, A., Fedorov, A.G.,

Samburskaya, T.A., Giebultowicz, T.M., “Interlayer 

Coupling in EuS/SrS, EuS/PbSe and EuS/PbTe Magnetic

Semiconductor Superlattices,” J. Phys.: Condens. Mat. 21

(12), 124207 (2009).

Khan, A.S., Meredith, C.S., “Thermo-Mechanical Response of Al

6061 with and Without Equal Channel Angular Pressing 

(ECAP),” Int. J. Plast., in press.

Khoadadadi, S., Pawlus, S., Sokolov, A.P., “Influence of Hydration 

on Protein Dynamics: Combining Dielectric and Neutron

Scattering Spectroscopy Data,” J. Phys. Chem. B 112 (45), 

14273 (2008). (CHRNS)

Kilburn, D., Sokol, P.E., Brown, C.M., “Inelastic Neutron

Scattering From Confined Molecular Oxygen,” Phys. Rev. B

78 (21), 214304 (2008). (CHRNS)

Kim, J.H., Ji, S., Lee, S.H., Lake, B., Yildirim, T., Nojiri, H.,

Kikuchi, H., Habicht, K., Qiu, Y., Kiefer, K., “External

Magnetic Field Effects on a Distorted Kagome 

Antiferromagnet,” Phys. Rev. Lett. 101 (10), 107201 (2008).

(CHRNS)

Kim, J.H., Lee, S.H., Park, S.I., Kenzelmann, M., Harris, A.B.,

Schefer, J., Chung, J.H., Majkrzak, C.F., Takeda, M., 

Wakimoto, S., Park, S.Y., Cheong, S.W., Matsuda, M.,

Kimura, H., Noda, Y., Kakurai, K., “Spiral Spin Structures

and Origin of the Magnetoelectric Coupling in YMn2O5,” 

Phys. Rev. B 78 (24), 245115 (2008).

Kim, M.H., Glinka, C.J., “Correlation between Structure and

Vapor Sorption in Semicrystalline Linear Polyethylene: 

One Dimensional Nano-Swelling Measured Using in Situ

Vapor Sorption Small Angle Neutron Scattering (iVSANS),” 

Macromol. 42 (7), 2618 (2009). (CHRNS)

Kim, T.H., Kang, S.H., Doe, C., Yu, J., Sim, J.B., Kim, J., Kline,

S.R., Choi, S.M., “Highly Ordered Self-Assembly of 1D

Nanoparticles in Phospholipids Driven by Curvature and 

Electrostatic Interaction,” J. Am. Chem. Soc. 131 (21), 7456 

(2009).

Kim, T.J., Kim, J.R., Sim, C.M., Lee, S.W., Kaviany, M., Son, S.Y., 

Kim, M.H., “Experimental Approaches for Distribution and 

Behavior of Water in PEMFC Under Flow Direction and 

Differential Pressure Using Neutron Imaging Technique,” 

Nucl. Instr. Meth. A 600 (1), 325 (2009).

King, G., Wills, A.S., Woodward, P.M., “Magnetic Structures of

NaLMnWO6 Perovskites (L=La,Nd,Tb),” Phys. Rev. B 79

(22), 224428 (2009).

Kirby, B.J., Kan, D., Luykx, A., Mrakami, M., Kundaliya, D.,

Takeuchi, I., “Anomalous Ferromagnetism in TbMnO3 Thin 

Films,” J. Appl. Phys. 105 (7), 07D917 (2009).

Kirby, B.J., Watson, S.M., Davies, J.E., Zimanyi, G.T., Liu, K., 

Shull, R.D., Borchers, J.A., “Direct Observation of Magnetic

Gradient in Co/Pd Pressure-Graded Media,” J. Appl. Phys.

105 (7), 07C929 (2009).

Kiryukhin, V., Lee, S., Ratcliff, W., Huang, Q., Yi, H.T., Choi, Y.J., 

Cheong, S.W., “Order by Static Disorder in the Ising Chain Magnet

Ca3Co2-xMnxO6,” Phys. Rev. Lett. 102 (18), 187202 (2009).

Klimczuk, T., McQueen, T.M., Williams, A.J., Huang, Q., Ronning, 

F., Bauer, E.D., Thompson, J.D., Green, M.A., Cava, R.J., 

“Superconductivity at 2.2 K in the Layered Oxypnictide

La3Ni4P4O2,” Phys. Rev. B 79 (1), 012505 (2009).

Klimczuk, T., Zandbergen, H.W., Huang, Q., McQueen, T.M., Ronning,

F., Kusz, B., Thompson, J.D., Cava, R.J., “Cluster-Glass Behavior of

a Highly Oxygen Deficient Perovskite, BaBi0.28Co0.72O2.2,” J. Phys.: 

Condens. Mat. 21 (10), 105801 (2009).

Knoll, W., Naumann, R., Friedrich, M., Robertson, J.W.F., Lösche, M.,

Heinrich, F., McGillivray, D.J., Schuster, B., Gufler, P.C., Pum, D.,

Sleyter, Y.B., “Solid Supported Lipid Membranes: New Concepts 

for the Biomimetic Functionalization of Solid Surfaces,” Biointerph. 

3 (2), FA125 (2008).

Kofu, M., Kim, J.H., Ji, S., Lee, S.H., Ueda, H., Qiu, Y., Kang, H.J., Green, 

M.A., Ueda, Y., “Weakly Coupled S = 1⁄2 Quantum Spin Singlets in

Ba3Cr2O8,” Phys. Rev. Lett. 102 (3), 037206 (2009). (CHRNS)

Kofu, M., Lee, S.H., Fujita, M., Kang, H.J., Eisaki, H., Yamada, K., 

“Hidden Quantum Spin-Gap State in the Static Stripe Phase of

High-Temperature La2-xSrxCuO4 Superconductors,” Phys. Rev. Lett. 

102 (4), 047001 (2009). (CHRNS)

Kofu, M., Qiu, Y., Bao, W., Lee, S.H., Chang, S., Wu, T., Wu, G., Chen, 

X.H., “Neutron Scattering Investigation of the Magnetic Order in 

Single Crystalline BaFe2As2,” New J. Phys. 11 (5), 055001 (2009).

(CHRNS)

Kothapalli, K., Nasreen, F., Peterson, J., Nakotte, H., El-Khatib, S., 

Vogel, S.C., Llobet, A., Reiche, H., Swainson, I., Brück, E., “Effect 

of Temperature on Hybridization and Magnetism in UPdSn and 

UCuSn,” J. Appl. Phys. 105 (7), 07E121 (2009).

Kravtsov, E., Haskel, D., te Velthuis, S.G.E., Jiang, J.S., Kirby, B.J.,

“Complementary Polarized Neutron and Resonant X-Ray Magnetic

Reflectometry Measurements in Fe/Gd Heterostructures: Case of

Inhomogeneous Intralayer Magnetic Structure,” Phys. Rev. B 79

(13), 134438 (2009).

Kreyssig, A., Green, M.A., Lee, Y., Samolyuk, G.D., Zajdel, P., Lynn, 

J.W., Bud’ko, S.L., Torikachvili, M.S., Ni, N., Nandi, S., Leão,

J.B., Poulton, S.J., Argyriou, D.N., Harmon, B.N., McQueeney, 

Canfield, P.C., Goldman, A.I., “Pressure-Induced Volume-Collapsed

Tetragonal Phase of CaFe2As2 as Seen via Neutron Scattering,” Phys. 

Rev. B 78 (18), 184517 (2008).

Krycka, K.L., Booth, R., Borchers, J.A., Chen, W.C., Conlon, C., Gentile, 

T., Hogg, C., Ijiri, Y., Laver, M., Maranville, B.B., “Resolving 3D

Magnetism in Nanoparticles Using Polarization Analyzed SANS,”

Physica B, in press. (CHRNS)

Krycka, K.L., Maranville, B.B., Borchers, J.A., Castaño, Ng, B.G., 

Perkinson, J.C., Ross, C.A., “Magnetic Domain Formation within 

Patterned NiFe/Cu/Co Ellipses,” J. Appl. Phys. 105 (7), 07C120 

(2009).

Publications
NCNR 2009 Accomplishments and Opportunities 71

Kučerka, N., Nagle, J.F., Sachs, J.N., Feller, S., Pencer, J., Jackson, 

A.J., Katsaras, J., “Lipid Bilayer Structure Determined by the 

Simultaneous Analysis of Neutron and X-Ray Scattering Data,” 

Biophys. J. 95 (5), 2356 (2008). (CHRNS)

Kumar, R., Raghavan, S.R., “Photogelling Fluids Based on LightActivated Growth and Zwitterionic Wormlike Micelles,” Soft Matter 

5 (4), 797 (2009). (CHRNS)

Lagi, M., Chu, X., Kim, S., Mallamace, F., Baglioni, P., Chen, S.-H., “The 

Low-Temperature Dynamic Crossover Phenomenon in Protein 

Hydration Water: Simulations vs Experiments,” J. Phys. Chem. B 

112 (6), 1571 (2008).

Lashley, J.C., Shapiro, S.M., Winn, B.L., Opeil, C.P., Manley, M.E., Atalas, 

A., Ratcliff, W., Park, T., Fisher, R.A., Mihaila, B., Riseborough, 

P., Salje, E.K., Smith, J.L., “Observation of a Continuous Phase 

Transition in a Shape-Memory Alloy,” Phys. Rev. Lett. 101 (13), 

135703 (2008).

Lashley, J.C., Stevens, R., Crawford, M.K., Boerio-Goates, J., Woodfield, 

B.F., Qiu, Y., Lynn, J.W., Goddard, P.A., Fisher, R.A., “Specific 

Heat and Magnetic Susceptibilities of the Spinels GeNi2O4 and 

GeCo2O4,” Phys. Rev. B 78 (10), 104406 (2008). (CHRNS)

Laver, M., Bowell, C.J., Forgan, E.M., Abrahamsen, A.B., Fort, D., 

Dewhurst, C.D., Mühlbauer, S., Christen, D.K., Kohlbrecher, J., 

Cubitt, R., Ramos, S., “Structure and Degeneracy of Vortex Lattice 

Domains in Pure Superconducting Niobium: A Small-Angle 

Neutron Scattering Study,” Phys. Rev. B 79 (1), 014518 (2009).

Law, B.M., Brown, M.D., Marchand, L., Lurio, L.B., Hamilton, W.A., 

Kuzmenko, I., Gog, T., Satija, S., Watkins, E., Majewski, J., 

“Adsorption at Liquid Interfaces: A Comparison of Multiple 

Experimental Techniques,” Eur. Phys. J. 167 (1), 127 (2009).

Lawes, G., Kenzelmann, M., Broholm, C., “Magnetically Induced 

Ferroelectricity in the Buckled Kagomé Antiferromagnet Ni3V2O8,” 

J. Phys.: Condens. Mat. 20 (43), 434205 (2008).

Lee, H.J., Soles, C.L., Vogt, B.D., Liu, D.W., Wu, W.L., Lin, E.K., Kim, 

H.C., Lee, V.Y., Volksen, W., Miller, R.D., “Effect of Porogen 

Molecular Architecture and Loading on Structure of Porous Thin 

Films,” Chem. Mater. 20 (24), 7390 (2008).

Lee, J.H., Danino, D., Raghavan, S.R., “Polymerizable Vesicles Based on 

a Single-Tailed Fatty Acid Surfactant: A Simple Route to Robust 

Nanocontainers,” Langmuir 25 (3), 1566 (2009). (CHRNS)

Lee, S., Choi, T., Ratcliff, W., Erwin, R., Cheong, S.W., Kiryukhin, 

V., “Single Ferroelectric and Chiral Magnetic Domain of SingleCrystalline BiFeO3 in an Electric Field,” Phys. Rev. B 78 (10), 

100101 (2008).

Lee, S., Chung, J.H., Liu, X., Furdyna, J.K., Kirby, B.J., “Ferromagnetic 

Semiconductor GaMnAs,” Mater. Today 12 (14), 14 (2009).

Lee, S., Tirumala, V.R., Nagao, M., Tominaga, T., Lin, E.K., Gong, 

J.P., Wu, W.L., “Dynamics in Multicomponent Polyelectrolyte 

Solutions,” Macromol. 42 (4), 1293 (2009). (CHRNS)

Lee, S.W., Hussey, D.S., Jacobson, D.L., Sim, C.M., Arif, M., 

“Development of the Grating Phase Neutron Interferometer at 

a Monochromatic Beam Line,” Nucl. Instr. Meth. A 605 (1), 16 

(2009).

Leighton, C., Stauffer, D.D., Huang, Q., Ren, Y., El-Khatib, S., Torija, 

M.A., Wu, J., Lynn, J.W., Wang, L., Frey, N.A., Srikantha, H., Davies, 

J.E., Liu, K., Mitchell, J.F., “Coupled Structural/Magnetocrystalline 

Anisotropy Transitions in the Doped Perovskite Cobaltite 

Pr1−xSrxCoO3,” Phys. Rev. B 79 (21), 214420 (2009).

Lelong, G., Bhattacharyya, S., Kline, S., Cacciaguerra, T., Gonzalez, 

M.A., Saboungi, M.-L., “Effect of Surfactant Concentration on the 

Morphology and Texture of MCM-41 Materials,” J. Phys. Chem. C 

112 (29), 10674 (2008). (CHRNS)

Li, J., Callaway D.J., Bu Z., “Ezrin Induces Long-Range Interdomain 

Allostery in the Scaffolding Protein NHERF1”, J. Mol. Biol., in 

press. (CHRNS)

Li, J., Jensen, T.B.S., Andersen, N.H., Zarestky, J.L., McCallum, R.W., 

Chung, J.H., Lynn, J.W., Vaknin, D., “Tweaking the Spin-Wave 

Dispersion and Suppressing the Incommensurate Phase in LiNiPO4

by Iron Substitution,” Phys. Rev. B 79 (17), 174435 (2009). (CHRNS)

Li, J., Singh, U.G., Schladt, T.D., Stalick, J.K., Scott, S.L., Seshadri, R., 

“Hexagonal YFe1−xPdxO3−δ: Nonperovskite Host Compounds for 

Pd2+ and Their Catalytic Activity for CO Oxidation,” Chem. Mater. 

20 (20), 6567 (2008).

Li, J., Tian, W., Chen, Y., Zarestky, J.L., Lynn, J.W., Vaknin, D., 

“Antiferromagnetism in the Magnetoelectric Effect Single Crystal 

LiMnPO4,” Phys. Rev. B 79 (14), 144410 (2009). (CHRNS)

Li, S., Chen, Y., Chang, S., Lynn, J.W., Li, L., Luo, Y., Cao, G., Xu, Z., 

Dai, P., “Spin Gap and Magnetic Resonance in Superconducting 

BaFe1.9Ni0.1As2,” Phys. Rev. B 79 (17), 174527 (2009). (CHRNS)

Li, S., de la Cruz, C., Huang, Q., Chen, G.F., Xia, T.L., Luo, J.L., Wang, 

N.L., Dai, P., “Structural and Magnetic Phase Transitions in Na1-

δFeAs,” Phys. Rev. B 80 (2), 020504 (2009).

Li, S., de la Cruz, C., Huang, Q., Chen, Y., Lynn, J.W., Hu, J., Huang, Y.L., 

Hsu, F.C., Yeh, K.W., Wu, M.K., Dai, P., “First-Order Magnetic and 

Structural Phase Transitions in Fe1+ySexTe1−x,” Phys. Rev. B 79 (5), 

054503 (2009).

Li, T., Hong, K., Porcar, L., Verduzco, R., Butler, P.D., Smith, G.S., Liu, 

Y., Chen, W.R., “Assess the Intramolecular Cavity of a PAMAM 

Dendrimer in Aqueous Solution by Small-Angle Neutron 

Scattering,” Macromol. 41 (22), 8916 (2008). (CHRNS)

Li, Y.C., Chen, C.Y., Chang, Y.X., Chuang, P.Y., Chen, J.H., Chen, H.L., 

Hsu, C.S., Ivanov, V.A., Khalatur, P.G., Chen, S.A., “Scattering 

Study of the Conformational Structure and Aggregation Behavior of 

a Conjugated Polymer Solution,” Langmuir 25 (8), 4668 (2009).

Liberatore, M.W., Nettesheim, F., Vasquez, P.A., Helgeson, M.E., Wagner, 

N.J., Kaler, E.W., Cook, L.P., Porcar, L., Hu, Y.T., “Microstructure 

and Shear Rheology of Entangled Wormlike Micelles in Solution,” J. 

Rheol. 53 (2), 441 (2009).
72

Lin, X., Telepeni, I., Blake, A.J., Dailly, A., Brown, C.M.,

Simmons, J.M., Zoppi, M., Walker, G.S., Thomas, K.M., 

Mays, T.J., Hubberstey, P., Champness, N.R., Schröder,

M., “High Capacity Hydrogen Adsorption in Cu(II) 

Tetracarboxylate Framework Materials: The Role of Pore

Size, Ligand Functionalization, and Exposed Metal Sites,” J. 

Am. Chem. Soc. 131 (6), 2159 (2009).

Lindstrom, R.M., Fischbach, E., Buncher, J.B., Greene, G.L.,

Jenkins, J.H., Krause, D.E., Mattes, J.J., and Yue, A., “Does

the Half-Life of a Radioactive Sample Depend on its 

Shape?,” Trans. Am. Nucl. Soc. 100, 225 (2009).

Lindstrom, R.M., Fleming, R.F., “Neutron Self-Shielding Factors

for Simple Geometries, Revisited,” Chem. Anal. (Warsaw) 

53, 855 (2008).

Lindstrom, R.M., Zeisler, R., Mackey, E.A., Liposky, P.J., 

Popelka-Filcoff, R.S., Williams, R.E., “Neutron Irradiation 

in Activation Analysis: A New Rabbit for the NBS,” J. 

Radioanal. Nucl. Chem. 278 (3), 665 (2008).

Liu, D., Yue, M., Zhang, J., McQueen, T.M., Lynn, J.W., Wang, X., 

Chen, Y., Li, J., Cava, R.J., Liu, X., Altounian, Z., Huang, 

Q., “Origin and Tuning of the Magnetocaloric Effect in the 

Magnetic Refrigerant Mn1.1Fe0.9(P0.8Ge0.2),” Phys. Rev. B 79

(1), 014435 (2009).

Liu, G., Huang, Q., Kaduk, J.A., Yang, Z., Lucas, C., Wong-Ng,

W., “X-Ray and Neutron Powder Diffraction Studies of

Ba(NdxY2−x)CuO5,” J. Solid State Chem. 181 (12), 3236 

(2008).

Liu, H.-T., Gnäupel-Herold, T., Hovanski, Y., Dahl, M.E., 

“Fatigue Performance Enhancement of AWJ-Machined 

Aircraft Aluminum with Dry-Grit Blasting,” in “Proceedings 

of the 2009 American WJTA Conference and Expo,” edited 

by Hashish, M. (Am WJTA Conf. Proc.), in press.

Liu, Y., Her, J.H., Dailly, A., Ramirez-Cuesta, A.J., Neumann,

D.A., Brown, C.M., “Reversible Structural Transition in 

MIL-53 with Large Temperature Hysteresis,” J. Am. Chem.

Soc. 130 (35), 11813 (2008). (CHRNS)

Liu, Y., Watson, S.M., Lee, T., Gorham, J.M., Katz, H.E., 

Borchers, J.A., Fairbrother, H.D., Reich, D.H., “Correlation

Between Microstructure and Magnetotransport in Organic

Semiconductor Spin-Valve Structures,” Phys. Rev. B 79 (7),

075312 (2009).

Livingston, R.A., Bumrongjaroen, W., Allen, A.J., “The

Fractal Ratio as a Metric of Nanostructure Development

in Hydrating Cement Paste,” in “Nanotechnology in

Construction 3,” edited by Bittnar, Z., Bartos, P.J.M.,

Němeček, J., Šmilauer, V., Zeman, J., (Springer Berlin

Heidelberg), Part 2, 101 (2009).

Luo, J., Xu, H., Liu, Y., Zhao, Y., Daemen, L.L., Brown, C., 

Timofeeva, T.V., Ma, S., Zhou, H.C., “Hydrogen Adsorption 

in a Highly Stable Porous Rare-Earth Metal-Organic

Framework: Sorption Properties and Neutron Diffraction

Studies,” J. Am. Chem. Soc. 130 (30), 9626 (2008).

Lynn, J.W., Dai, P., “Neutron Studies of the Iron-Based Family of High TC

Magnetic Superconductors,” Physica C 469 (9), 469 (2009).

Ma, S., Simmons, J.M., Li, J.R., Yuan, D., Wang, W., Liu, D.J., Zhou, 

H.C., “A Nanotubular Metal-Organic Framework with Permanent

Porosity: Structure Analysis and Gas Sorption Studies,” Chem.

Commun. 4049 (2009).

Ma, S., Simmons, J.M., Sun, D., Yuan, D., Zhou, H.C., “Porous MetalOrganic Frameworks Based on an Anthracene Derivative: Syntheses, 

Structure Analysis, and Hydrogen Sorption Studies,” Inorg. Chem.

48 (12), 5263 (2009).

Mackey, E.A., Spatz, R.O., “Assessment of Stability of Trace Elements in 

Two Natural Matrix Environmental Standard Reference Materials: 

NIST-SRM 1547 Peach Leaves and NIST-SRM 1566a Oyster

Tissue,” J. Radioanal. Nucl. Chem. 281 (1), 91 (2009).

Majkrzak, C.F., Berk, N.F., Kienzle, P., Perez-Salas, U., “Progress in the

Development of Phase-Sensitive Neutron Reflectometry Methods,”

Langmuir 25 (7), 4154 (2009).

Mamontov, E., Cole, D.R., Dai, S., Pawel, M.D., Liang, C.D., Jenkins, T.,

Gasparovic, G., Kintzel, E., “Dynamics of Water in LiCl and CaCl2

Aqueous Solutions Confined in Silica Matrices: A Backscattering 

Neutron Spectroscopy Study,” Chem. Phys. 352 (1), 117 (2008). 

(CHRNS)

Mamontov, E., Vlcek, L., Wesolowski, D.J., Cummings, P.T., Rosenqvist,

J., Wang, W., Cole, D.R., Anovitz, L.M., Gasparovic, G., 

“Suppression of the Dynamic Transition in Surface Water at Low 

Hydration Levels: A Study of Water on Rutile,” Phys. Rev. E 79 (5),

051504 (2009). (CHRNS)

Manley, M.E., Sievers, A.J., Lynn, J.W., Kiselev, S.A., Agladze, N.I., Chen, 

Y., Llobet, A., Alatas, A., “Intrinsic Localized Modes Observed in

the High-Temperature Vibrational Spectrum of NaI,” Phys. Rev. B

79 (13), 134304 (2009).

Manson, J.L., Lancaster, T., Blundell, S.J., Qiu, Y., Singleton, J., Sengupta,

P., Pratt, F.L., Kang, J., Lee, C., and Whangbo, M.H., “Spin

Fluctuations and Orbital Ordering in Quasi-One-Dimensional

α-Cu(dca)2(pyz) {dca=Dicyanamide=N(CN)2; pyz=Pyrazine}, a

Molecular Analogue of KCuF3,” Polyhedron, in press. (CHRNS)

Marszalek, J., Pojman, J.A., “Neutron Scattering Study of the Structural

Change Induced by Photopolymerization of AOT/D2O/Dodecyl

Acrylate Inverse Microemulsions,” Langmuir 24 (23), 13694 (2008).

(CHRNS)

Mayumi, K., Endo, H., Osaka, N., Yokoyama, H., Nagao, M., Shibayama, 

M., Ito, K., “Mechanically Interlocked Structure of Polyrotaxane

Investigated by Contrast Variation Small-Angle Neutron Scattering,”

Macromol., in press.

Mayumi, K., Nagao, M., Endo, H., Osaka, N., Shibayama, M., Ito, K., 

“Dynamics of Polyrotaxane Investigated by Neutron Spin Echo

Technique,” Physica B, in press. (CHRNS)

Publications
NCNR 2009 Accomplishments and Opportunities 73

McGillivray, D.J., Valincius, G., Heinrich, F., Robertson, J.W.F., Vanderah, 

D.J., Febo-Ayala, W., Ignatjev, I., Lösche, M., Kasianowicz, J.J., 

“Structure of Functional Staphylococcus Aureus α-Hemolysin 

Channels in Tethered Bilayer Lipid Membranes,” Biophys. J. 96 (4), 

1547 (2009).

McIver, J.W., Erwin, R., Chen, W.C., Gentile, T.R., “End-Compensated 

Magnetostatic Cavity for Polarized 3

He Neutron Spin Filters,” Rev. 

Sci. Instrum. 80 (6), 063905 (2009).

McQueen, T.M., Huang, Q., Ksenofontov, V., Felser, C., Xu, Q., 

Zandbergen, H., Hor, Y.S., Allred, J., Williams, A.J., Qu, D., 

Checkelsky, J., Ong, N.P., Cava, R.J., “Extreme Sensitivity of 

Superconductivity to Stoichiometry in Fe1+δSe,” Phys. Rev. B 79 (1), 

014522 (2009).

McQueen, T.M., Klimczuk, T., Williams, A.J., Huang, Q., Cava, R.J., 

“Stoichiometry, Spin Fluctuations, and Superconductivity in 

LaNiPO,” Phys. Rev. B 79 (17), 172502 (2009).

McQueen, T.M., Stephens, P.W., Huang, Q., Klimczuk, T., Ronning, F., 

Cava, R.J., “Successive Orbital Ordering Transitions in NaVO2,” 

Phys. Rev. Lett. 101 (16), 166402 (2008).

Melnichenko, Y.B., Radlinski, A.P., Mastalerz, M., Cheng, G., Rupp, 

J.A., “Characterization of the CO2 Fluid Adsorption in Coal as a 

Function of Pressure Using Neutron Scattering Techniques (SANS 

and USANS),” Int. J. Coal Geo. 77 (2), 69 (2009). (CHRNS)

Meure, L.A., Knott, R., Foster, N.R., Dehghani, F., “The Depressurization 

of an Expanded Solution into Aqueous Media for the Bulk 

Production of Liposomes,” Langmuir 25 (1), 326 (2009).

Mikel, S.E., Biernacki, J.J., Gnaeupel-Herold, T., “A Neutron DiffractionBased Technique for Determining Phase Resolved Strains in 

Portland Cement,” ACI Mater. J., in press.

Millican, J., Phelan, D., Thomas, E.L., Leão, J.B., Carpenter, E., “PressureInduced Effects on the Structure of the FeSe Superconductor,” Solid 

State Commun. 149 (17), 707 (2009).

Moore, R.G., Lumsden, M.D., Stone, M.B., Zhang, J., Chen, Y., Lynn, 

J.W., Jin, R., Mandrus, D., Plummer, E.W., “Phonon Softening and 

Anomalous Mode Near the xc=0.5 Quantum Critical Point in 

Ca2−xSrxRuO4,” Phys. Rev. B 79 (17), 172301 (2009).

Mühlbauer, S., Pfleiderer, C., Böni, P., Laver, M., Forgan, E.M., Fort, D., 

Keiderling, U., Behr, G., “Morphology of the Superconducting 

Vortex Lattice in Ultrapure Niobium,” Phys. Rev. Lett. 102 (13), 

136408 (2009).

Mukherjee, P.P., Springer, T., Mukundan, Hussey, D.S., Jacobson, D., Arif, 

M., and Borup, R.L., “Probing Liquid Water Profile in the Polymer 

Electrolyte Fuel Cell Membrane,” ECS Trans. 16 (2), 1027 (2008).

Mukundan, R., Davey, J., Lujan, R., Spendelow, J., Kim, Y.S., Hussey, D.S., 

Jacobson, D., Arif, M., Borup, R.L., “Performance and Durability 

of PEM Fuel Cells Operated at Sub-Freezing Temperatures,” ECS 

Trans. 16 (2), 1939 (2008).

Murthi, V.S., Dura, J.A., Satija, S.K., Majkrzak, C.F., “Water Uptake and 

Interfacial Structural Changes of a Perfluorosulfonic Acid Ionomer 

Membranes Measured by Neutron Reflectivity for PEM Fuel Cells,” 

ECS Trans. 16 (2), 1471 (2008).

Nagao, M., Seto H., “Full Fitting Analysis of the Relative Intermediate 

Form Factor Measured by Neutron Spin Echo,” Physica B, in press.

(CHRNS)

Nayak, A., Sorci, M., Krueger, S., Belfort, G., “A Universal Pathway for 

Amyloid Nucleus and Precursor Formation for Insulin,” Proteins 74

(3), 556 (2009).

Nedoma, A.J., Robertson, M.L., Wanakule, N.S., Balsara, N.P., 

“Measurements of the Composition and Molecular Weight 

Dependence of the Flory−Huggins Interaction Parameter,” 

Macromol. 41 (15), 5773 (2008). (CHRNS)

Nettesheim, F., Liberatore, M.W., Hodgdon, T.K., Wagner, N.J., Kaler, 

E.W., Vethamuthu, M., “Influence of Nanoparticle Addition on 

the Properties of Wormlike Micellar Solutions,” Langmuir 24 (15), 

7718 (2008).

Nieh, M.P., Guiver, M.D., Kim, D.S., Ding, J., Norsten, T., “Morphology 

of Comb-Shaped Proton Exchange Membrane Copolymers Based 

on a Neutron Scattering Study,” Macromol. 41 (16), 6176 (2008).

Nieh, M.-P., Yamani, Z., Kucerka, N., Katsaras, J., Burgess, D., Breton, 

H., “Adapting a Triple-Axis Spectrometer for Small Angle Neutron 

Scattering Measurements,” Rev. Sci. Instrum. 79 (9), 095102 (2008).

Odette, G.R., Alinger, M.J., Wirth, B.D., “Recent Developments in 

Irradiation-Resistant Steels,” Annu. Rev. Mater. Sci. 38, 471 (2008).

Olsen, B.D., Shah, M., Ganesan, V., Segalman, R.A., “Universalization 

of the Phase Diagram for a Model Rod−Coil Diblock Copolymer,” 

Macromol. 41 (18), 6809 (2008). (CHRNS)

Page, K., Li, J., Savinelli, R., Szumila, H.N., Zhang, J., Stalick, J.K., 

Proffen, T., Scott, S.L., Seshadri, R., “Reciprocal-Space and RealSpace Neutron Investigation of Nanostructured Mo2C and WC,” 

Solid State Sci. 10 (11), 1499 (2008). 

Page, K.A., Park, J.K., Moore, R.B., Garcia Sakai, V., “Direct Analysis 

of the Ion-Hopping Process Associated with the α-Relaxation 

in Perfluorosulfonate Ionomers Using Quasielastic Neutron 

Scattering,” Macromol. 42 (7), 2729 (2009). (CHRNS)

Page, M.G., Warr, G.G., “Influence of the Structure and Composition of 

Mono- and Dialkyl Phosphate Mixtures on Aluminum Complex 

Organogels,” Langmuir 25 (15), 8810 (2009). (CHRNS)

Park, J., Li, X., Tran, D., Abdel-Baset, T., Hussey, D.S., Jacobson, 

D.L., Arif, M., “Neutron Imaging Investigation of Liquid Water 

Distribution in and the Performance of a PEM Fuel Cell,” Int. J. 

Hydrogen Energy 33 (13), 3373 (2008). 
74

Park, J., Watson, S.M., Furjanic, C.M., Draganova, D.K., Chen, 

C.Y., Borchers, J.A., Carey, M.J., Sparks, P.D., Eckert, J.C.,

“Probing the Effect of Structural Roughness on Domain

Wall Formation in Spin Valves Using Off-Specular 

Reflectivity Techniques,” IEEE Trans. Mag. 44 (11), 2839

(2008).

Park, M.J., Balsara, N.P., Jackson, A., “Order−Disorder

Transitions in Block Copolymer Electrolytes at Equilibrium 

with Humid Air,” Macromol., in press. (CHRNS)

Park, S., Fitzsimmons, M.R., Majkrzak, C.F., Schultz, B.D., 

Palmstrøm, C.J., “The Influence of Growth Temperature

and Annealing on the Magnetization Depth Profiles Across 

Ferromagnetic/Semiconductor Interfaces,” J. Appl. Phys. 

104 (8), 083905 (2008).

Paul, R.L., Lindstrom, R.M., Brocker, C., Mackey, E.A., “Design

of a New Instrument for Cold Neutron Prompt Gamma-Ray 

Activation Analysis at NIST,” J. Radioanal. Nucl. Chem. 278

(3), 697 (2008).

Peterson, V.K., Whitten, A.E., “Hydration Processes in Tricalcium 

Silicate: Application of the Boundary Nucleation Model to

Quasielastic Neutron Scattering Data,” J. Phys. Chem. C 113

(6), 2347 (2009).

Phelan, D., Louca, D., Ancona, S.N., Rosenkranz, S., Zheng, H.,

Mitchell, J.F., “Neutron Scattering Study of the Competing 

Magnetic Correlations in La0.85Sr0.15CoO3,” Phys. Rev. B 79

(9), 094420 (2009). (CHRNS)

Phelan, D., Millican, J.N., Thomas, E.L., Leão, J.B., Qiu, Y., Paul,

R., “Neutron Scattering Measurements of the Phonon

Density of States of FeSe1−x Superconductors,” Phys. Rev. B

79 (1), 014519 (2009). (CHRNS)

Phelan, D., Yu, J., Louca, D., “Jahn-Teller Spin Polarons in 

Perovskite Cobaltites,” Phys. Rev. B 78 (9), 094108 (2008).

Porcar, L., Liu, Y., Hong, K., Butler, P.D., Huang, E.W., 

Chen, W.R., “Counterion Association and Structural

Conformation Change of Charged PAMAM Dendrimer

in Aqueous Solutions Revealed by Small Angle Neutron

Scattering,” Macromol. Symp. 279 (1), 65 (2009). (CHRNS)

Porcar, L., Liu, Y., Verduzco, R., Hong, K., Butler, P.D., Magid, 

L.J., Smith, G.S., Chen, W.R., “Structural Investigation of 

PAMAM Dendrimers in Aqueous Solutions Using SmallAngle Neutron Scattering: Effect of Generation,” J. Phys.

Chem. B 112 (47), 14772 (2008). (CHRNS)

Pozzo, D.C., “Neutron-Scattering Probe of Complexes of Sodium

Dodecyl Sulfate and Serum Albumin During Polyacrylamide

Gel Electrophoresis,” Langmuir 25 (3), 1558 (2009).

Prabhu, V.M., Rao, A., Kang, S., Lin, E.K., Satija, S.K.,

“Manipulation of the Asymmetric Swelling Fronts of

Photoresist Polyelectrolyte Gradient Thin Films,” J. Phys.

Chem. B 112 (49), 15628 (2008).

Prodi, A., Gilioli, E., Cabassi, R., Bolzoni, F., Licci, F., Huang, Q., Lynn, 

J.W., Affronte, M., Gauzzi, A., Marezio, M., “Magnetic Structure of

the High-Density Single-Valent eg Jahn-Teller System LaMn7O12,”

Phys. Rev. B 79 (8), 085105 (2009).

Psurek, T., Soles, C.L., Page, K.A., Cicerone, M.T., Douglas, J.F., 

“Quantifying Changes in the High-Frequency Dynamics of

Mixtures by Dielectric Spectroscopy,” J. Phys. Chem. B 112 (50), 

15980 (2008). (CHRNS)

Purewal, J.J., Keith, J.B., Ahn, C.C., Fultz, B., Brown, C.M., Tyagi, M.,

“Adsorption and Melting of Hydrogen in Potassium-Intercalated

Graphite,” Phys. Rev. B 79 (5), 054305 (2009). (CHRNS)

Pushin, D.A., Arif, M., Cory, DG., “Decoherence-Free Neutron

Interferometry,” Phys. Rev. A 79 (5), 053635 (2009).

Pynn, R., Fitzsimmons, M.R., Lee, W.T., Stonaha, P., Shah, V.R.,

Washington, A.L., Kirby, B.J., Majkrzak, C.F., Maranville, B.B.,

“Birefringent Neutron Prisms for Spin Echo Scattering Angle 

Measurement,” Physica B, in press.

Qiu, D., Cosgrove, T., Revell, P., Howell, I., “Poly(ethylene oxide)

Adsorption on Polystyrene Latex Particles in the Presence of

Poly(styrenesulfonate sodium),” Macromol. 42 (2), 547 (2009).

Qiu, Y., Bao, W., Huang, Q., Yildirim, T., Simmons, J.M., Green, M.A.,

Lynn, J.W., Gasparovic, Y.C., Li, J., Wu, T., Wu, G., Chen, X.H.,

“Crystal Structure and Antiferromagnetic Order in NdFeAsO1-xFx

(x = 0.0 and 0.2) Superconducting Compounds From Neutron 

Diffraction Measurements,” Phys. Rev. Lett. 101 (25), 257002

(2008).

Qiu, Y., Bao, W., Zhao, Y., Broholm, C., Stanev, V., Tesanovic, Z., 

Gasparovic, Y.C., Chang, S., Hu, J., Qian, B., Fang, M., Mao,

Z., “Spin Gap and Resonance at the Nesting Wave Vector in 

Superconducting FeSe0.4Te0.6,” Phys. Rev. Lett., in press. (CHRNS)

Qiu, Y., Kofu, M., Bao, W., Lee, S.-H., Huang, Q., Yildirim, T., Copley,

J.R.D., Lynn, J.W., Wu, T., Wu, G., Chen, X.H., “Neutron Scattering 

Study of the Oxypnictide Superconductor LaO0.87F0.13FeAs,” Phys.

Rev. B 78 (5), 052508 (2008). (CHRNS)

Qu, Z., Spinu, L., Yuan, H., Dobrosavljević, V., Bao, W., Lynn, J.W.,

Nicklas, M., Peng, J., Liu, T., Fobes, D., Flesch, E., Mao, Z.Q., 

“Unusual Heavy-Mass Nearly Ferromagnetic State with a 

Surprisingly Large Wilson Ratio in the Double Layered Ruthenates 

(Sr1−xCax)3Ru2O7,” Phys. Rev. B 78 (18), 180407 (2008).

Radlinski, A.P., Busbridge, T.L., Gray, E.M.A., Blach, T.P., Cheng, 

G., Melnichenko, Y.B., Cookson, D.J., Mastalerz, M., Esterle, J., 

“Dynamic Micromapping of CO2 Sorption in Coal,” Langmuir 25

(4), 2385 (2009). (CHRNS)

Rahatekar, S.S., Koziol, K.K., Kline, S.R., Hobbie, E.K., Gilman, 

J.W., Windle, A.H., “Length-Dependent Mechanics of CarbonNanotube Networks,” Adv. Mater. 21 (8), 874 (2008). 

Publications
NCNR 2009 Accomplishments and Opportunities 75

Ramachandran, R., Beaucage, G., Kulkarni, A.S., “Persistence Length of 

Short-Chain Branched Polyethylene,” Macromol. 41 (24), 9802 

(2008). (CHRNS)

Ramachandran, R., Beaucage, G., Kulkarni, A.S., McFaddin, D., MerrickMack, J., Galiatsatosm V., “Branch Content of Metallocene 

Polyethylene,” Macromol. 42 (13), 4746 (2009).

Ratcliff II, W., Sharma, A.L.L., Gomes, A.M., Gonzalez, J.L., Huang, Q., 

Singleton, J., “The Magnetic Ground State of CaMn2Sb2,” J. Magn. 

Magn. Mater., in press. 

Rekas, A., Lo, V., Gadd, G.E., Cappai, R., Yun, S.I., “PAMAM 

Dendrimers as Potential Agents against Fibrillation of -Synuclein, a 

Parkinson’s Disease-Related Protein,” Macromol. Biosci. 9 (3), 230 

(2009). (CHRNS)

Reynolds, P.A., McGillivray, D.J., Jackson, A.J., White, J.W., “Ultra-SmallAngle Neutron Scattering: A Tool to Study Packing of Relatively 

Monodisperse Polymer Spheres and Their Binary Mixtures,” Phys. 

Rev. E 80 (1), 011301 (2009). (CHRNS)

Ricciardo, R.A., Hauser, A.J., Yang, F.Y., Kim, H., Lu, W., Woodward, 

P.M., “Structural, Magnetic, and Electronic Characterization of 

Double Perovskites BixLa2− xMnMO6 (M= Ni, Co; x = 0.25, 0.50),” 

Mater. Res. Bull. 44 (2), 239 (2009).

Rimmer, C.A., Howerton, S.B., Sharpless, K.E., Sander, L.C., Long, 

S.E., Murphy, K.E., Porter, B.J., Putzbach, K., Rearick, M.S., Wise, 

S.A., Wood, L.J., Zeisler, R., Hancock, D.K., Yen, J.H., Betz, J.M., 

NguyenPho, A., Yang, L., Scriver, C., Willie, S., Sturgeon, R., 

Schaneberg, B., Nelson, C., Skamarack, J., Pan, M., Levanseler, K., 

Gray, D., Waysek, E.H., Blatter, A., Reich, E., “Characterization of 

a Suite of Ginko-Containing Standard Reference Materials,” Anal. 

Bioanal. Chem. 389, 179 (2007).

Roh, J.H., Briber, R.M., Damjanovic, A., Thirumalai, D., Woodson, 

S.A., Sokolov, A.P., “Dynamics of tRNA at Different Levels of 

Hydration,” Biophys. J. 96 (7), 2755 (2009). (CHRNS)

Ross, N.L., Spencer, E.C., Levchenko, A.A., Kolesnikov, A.I., Wesolowski, 

D.J., Cole, D.R., Mamontov, E., Vlcek, L., “Studies of MineralWater Surfaces,” in “Neutron Applications in Earth, Energy and 

Environmental Sciences,” edited by Liang, L., Rinaldi, R., Schober, 

H., (Springer US) Chap. 8, 235 (2009). (CHRNS)

Rubinson, K.A., Hubbard, J., “Experimental Compressibilities and 

Average Intermolecular Distances of Poly(Ethylene Glycol) 

Molecular Masses 2000–8000 Da in Aqueous Solution,” Polymer 50

(12), 2618 (2009).

Ruff, J.P., Clancy, J.P., Bourque, A., White, M.A., Ramazanoglu, M., 

Gardner, J.S., Qiu, Y., Copley, J.R.D., Johnson, M.B., Dabkowska, 

H.A., Gaulin, B.D., “Spin Waves and Quantum Criticality in the 

Frustrated XY Pyrochlore Antiferromagnet Er2Ti2O7,” Phys. Rev. 

Lett. 101 (14), 147205 (2008). (CHRNS)

Rughani, R.V., Salick, D.A., Lamm, M.S., Yucel, T., Pochan, D.J., 

Schneider, J.P., “Folding, Self-Assembly, and Bulk Material 

Properties of a De Novo Designed Three-Stranded β-Sheet 

Hydrogel,” Biomacromol. 10 (5), 1295 (2009). (CHRNS)

Rule, K.C., Bonville, P., “Tetragonal Distortion in Tb2Ti2O7 Seen by 

Neutron Scattering,” J. Phys.: Conf. Series 145, 012027-1 (2009). 

(CHRNS)

Russo, D., Teixeira, J., Ollivier, J., “The Impact of Hydration Water on 

the Dynamics of Side Chains of Hydrophobic Peptides: From Dry 

Powder to Highly Concentrated Solutions,” J. Chem. Phys. 130

(23), 235101 (2009). (CHRNS)

Sahoo, P., Adarsh, N.N., Chacko, G.E., Raghavan, S.R., Puranik, V.G., 

Dastidar, P., “Combinatorial Library of Primaryalkylammonium 

Dicarboxylate Gelators: A Supramolecular Synthon Approach,” 

Langmuir, in press.

Saines, P.J., Kennedy, B.J., Johannessen, B., Poulton, S., “Phase and Valence 

Transitions in Ba2LnSnxNb1-xO6-δ,” J. Solid State Chem. 181 (11), 

2994 (2008).

Sakiyama, N., Zaliznyak, I.A., Lee, S.H., Mitsui, Y., Yoshizawa, H., 

“Doping-Dependent Charge and Spin Superstructures in Layered 

Cobalt Perovskites,” Phys. Rev. B 78 (18), 180406 (2008).

Sakiyama, N., Zaliznyak, I.A., Lee, S.H., Mitsui, Y., Yoshizawa, H., “Spin 

and Charge Order in Single-Layered Perovskite Cobaltates,” J. 

Korean Phys. Soc. 53 (2), 995 (2008).

Schaefer, D.W., Zhao, J., Dowty, H., Alexander, M., Orler, E.B., “Carbon 

Nanofibre Reinforcement of Soft Materials,” Soft Matter 4 (10), 

2071 (2008).

Schexnailder, P., Loizou, E., Porcar, L., Butler, P., Schmidt, G., 

“Heterogeneity in Nanocomposite Hydrogels from Poly(Ethylene 

Oxide) Cross-Linked with Silicate Nanoparticles,” Phys. Chem. 

Chem. Phys. 11, 2760 (2009). (CHRNS)

Seah, M.P., Unger, W.E.S., Wang, H., Jordaan, W., Gross, T., Dura, J.A., 

Moon, D.W., Totarong, P., Krumrey, M., Hauert, R., Zhiqiang, M., 

“Ultra-Thin SiO2 on Si IX: Absolute Measurements of the Amount 

of Silicon Oxide as a Thickness of SiO2 on Si,” Surf. Interface Anal. 

41 (5), 430 (2009).

Seibell II, H.A., Karen, P., Wagner, T.R., Woodward, P.M., “Synthesis 

and Characterization of Color Variants of Nitrogen- and FluorineSubstituted TiO2,” J. Mater. Chem. 19, 471 (2009).

Seo, P.N., Barrón-Palos, L., Bowman, J.D., Chupp, T.E., Crawford, C., 

Dabaghyan, M., Dawkins, M., Freedman, S.J., Gentile, T., Gericke, 

M.T., Gillis, R.C., Green, G.L., Hersman, F.W., Jones, G.L., Kandes, 

M., Lamoureaux, S., Lauss, B., Leuschner, M.B., Mahurin, R., 

Mason, M., Mei, J., Mitchell, G.S., Nann, H., Page, S.A., Penttilä, 

S.I., Ramsay, W.D., Bacci, A.S., Santra, S., Sharma, M., Smith, T.B., 

Snow, W.M., Wilburn, W.S., Zhu, H., “High-Efficiency Resonant 

RF Spin Rotator with Broad Phase Space Acceptance for Pulsed 

Polarized Cold Neutron Beams,” Phys. Rev. ST Accel. Beams 11 (8), 

084701 (2008).
76

Sha, H., Ye, F., Dai, P., Fernandez-Baca, J.A., Mesa, D., Lynn, J.W.,

Tomioka, Y., Tokura, Y., Zhang, J., “Signature of Magnetic 

Phase Separation in the Ground State of Pr1−xCaxMnO3,”

Phys. Rev. B 78 (5), 052410 (2008).

Sharma, M., Babcock, E., Andersen, K.H., Barrón-Palos, 

L., Becker, M., Boag, S., Chen, W.C., Chupp, T.E.,

Danagoulian, A., Gentile, T.R., Klein, A., Penttila, S.,

Petoukhov, A., Soldner, T., Tardiff, E.R., Walker, T.G.,

Wilburn, W.S., “Neutron Beam Effects on Spin-ExchangePolarized 3

He,” Phys. Rev. Lett. 101 (8), 083002 (2008).

Shibayama, M., Matsunaga, T., Nagao, M., “Evaluation of

Incoherent Scattering Intensity by Transmission and Sample

Thickness,” J. Appl. Crystallogr., in press.

Shlyk, L.V., Kryukov, S.A., De Long, L.E., Schupp-Niewa,

B., Niewa, R., Lynn, J.W., Huang, Q., Arenholz, E., 

Piamonteze, C., “A Novel Class of High-TC Ferromagnetic

Semiconductors: Novel Ferromagnetic Semiconductors,”

UGIM Symp. Proc., 142 (2008).

Shoenfelt, J., Mitkus, R.A., Zeisler, R., Spatz, R.O., Powell, J.,

Fenton, M.J., Squibb, K.A., Medvedev, A.E., “Involvement 

of TLR2 and TLR4 in Inflammatory Immune Responses

Induced by Fine and Coarse Ambient Air Particulate 

Matter,” J. Leuk. Biol., in press.

Siegel, J.B., McKay, D.A., Stefanopoulou, A.G., Hussey, 

D.S., Jacobson, D.L., “Measurement of Liquid Water

Accumulation in a PEMFC with Dead-Ended Anode,” J. 

Electrochem. Soc. 155 (11), B1168 (2008).

Singh, D.K., Helton, J.S., Chu, S., Han, T.H., Bonnoit, C.J.,

Chang, S., Kang, H.J., Lynn, J.W., Lee, Y.S., “Spin

Correlations in the Geometrically Frustrated Pyrochlore

Tb2Mo2O7,” Phys. Rev. B 78 (22), 220405 (2008). (CHRNS)

Singh, I., Themistou, E., Porcar, L., Neelamagham, S., “Fluid Shear 

Induces Conformation Change in Human Blood Protein 

von Willebrand Factor in Solution,” Biophys. J. 96 (6), 2313 

(2009). (CHRNS)

Skripov, A.V., Udovic, T.J., Cook, J.C., Hempelmann, R., Rempel, 

A.A., Gusev, A.I., “Quasielastic Neutron Scattering Study of

Hydrogen Motion in NbC0.71H0.28,” J. Phys.: Condens. Mat.

21 (17), 175410 (2009). (CHRNS)

Skripov, A.V., Wu, H., Udovic, T.J., Huang, Q., Hempelmann,

R., Soloninin, A.V., Rempel, A.A., Gusev, A.I., “Hydrogen 

in Nonstoichiometric Cubic Niobium Carbides: Neutron

Vibrational Spectroscopy and Neutron Diffraction Studies,”

J. Alloys Compd. 478 (1), 68 (2009).

Sokolov, D.A., Aronson, M.C., Erwin, R., Lynn, J.W., Lumsden,

M.D., Nagler, S.E., “Neutron Diffraction in a Model

Itinerant Metal near a Quantum Critical Point,” J. Phys.:

Conf. Ser. 150 (4), 042189 (2009).

Spendelow, J., Mukundan, R., Davey, J., Rockward, T., Hussey, D.S., 

Jacobson, D., Arif, M., Borup R.L., “High Resolution Neutron

Radiography Imaging of Operating PEM Fuel Cells: Effect of Flow

Configuration and Gravity on Water Distribution,” ECS Trans. 16

(2), 1345 (2008).

Spernjak, D., Advani, S.G., Prasad, A.K., “Simultaneous Neutron and

Optical Imaging in PEM Fuel Cells,” J. Electrochem. Soc. 156 (1), 

B109 (2009).

Stalick, J.K., Waterstrat, R.M., “The Crystal Structure of Martensitic ZrIr 

and ZrRh,” J. Alloys Compd. 477 (1), 123 (2009).

Stewart, J.R., Gardner, J.S., Qiu, Y., Ehlers, G., “Collective Dynamics in 

the Heisenberg Pyrochlore Antiferromagnet Gd2Sn2O7,” Phys. Rev.

B 78 (13), 132410 (2008). (CHRNS)

Stock, C., Buyers, W.J.L., Rule, K.C., Chung, J.H., Liang, R., Bonn, D., 

Hardy, W.N., “Magnetic Field Resonantly Enhanced Free Spins in 

Heavily Underdoped YBa2Cu3O6+x,” Phys. Rev. B 79 (18), 184514 

(2009).

Stock, C., Chapon, L.C., Adamopoulos, O., Lappas, A., Giot, M., Taylor, 

J.W., Green, M.A., Brown, C.M., Radaelli, P.G., “One-Dimensional

Magnetic Fluctuations in the Spin-2 Triangular Lattice α-NaMnO2,”

Phys. Rev. Lett. in press. (CHRNS)

Sun, K., Kumar, R., Falvey, D.E., Raghavan, S.R., “Photogelling Colloidal

Dispersions Based on Light-Activated Assembly of Nanoparticles,” J.

Am. Chem. Soc. 131 (20), 7135 (2009). (CHRNS)

Sung, L., Gu, X., Clerici, C., Hu, H., Delaurent, V., “Metrologies 

for Characterizing Optical Properties of Clear and Pigmented 

Coatings,” in “Service Life Prediction for Polymeric Materials:

Global Perspectives,” edited by Martin, J., Ryntz, R., Chin, J., and

Dickie, R., (Springer US) Chap. 17, 257 (2008).

Sung, L., Gu, X., Clerici, C., Hu, H., Loizou, E., Ho, D.L., “Effect of

Pigment Dispersion on Optical Properties and Durability of a 

TiO2 Pigmented Epoxy Coating,” in “Polymer Degradation and 

Performance,” edited by Celina, M.C., Wiggins, J., and Billingham, 

N., (ACS Publications) ACS Symp. Ser. 1004, Chap. 23, 276 

(2009).

Sung, L., Gu, X., Ho, D.L., Landis, F.A., Nguyen, D., “Effect of

Composition and Processing Condition on Surface Morphology 

and Microstructural Properties of Fluoropolymer/Acrylic Blends,” 

Chin. J. Polym. Sci. 27 (1), 59 (2009).

Swainson, I.P., Stock, C., Gehring, P.M., Xu, G., Hirota, K., Qiu, Y., Luo, 

H., Zhao, X., Li, J.-F., Viehland, D., “Soft Phonon Columns on the 

Edge of the Brillouin Zone in the Relaxor PbMg1/3Nb2/3O3,” Phys.

Rev. B 79 (22), 224301 (2009). (CHRNS)

Taherizadeh, A., Ghaei, A., Green, D.E., Altenhof, W.J., “Finite Element

Simulation of Springback for a Channel Draw Process with 

Drawbead Using Different Hardening Models,” Int. J. Mech. Sci. 51

(4), 314 (2009).

Publications
NCNR 2009 Accomplishments and Opportunities 77

Tan, K.T., Vogt, B.D., White, C.C., Steffens, K.L., Goldman, J., Satija, 

S.K., Clerici, C., Hunston, D.L., “On the Origins of Sudden 

Adhesion Loss at a Critical Relative Humidity: Examination of Bulk 

and Interfacial Contributions,” Langmuir 24 (17), 9189 (2008).

Taribagil, R.R., Hillmyer, M.A., Lodge, T.P., “A Compartmentalized 

Hydrogel from a Linear ABC Terpolymer,” Macromol. 42 (6), 1796 

(2009).

Terech, P., Dourdain, S., Bhat, S., Maitra, U., “Self-Assembly of Bile 

Steroid Analogues: Molecules, Fibers, and Networks,” J. Phys. 

Chem. B 113 (24), 8252 (2009).

Terech, P., Maitra, U., “Structural and Rheological Properties of Aqueous 

Viscoelastic Solutions and Gels of Tripodal Cholamide-Based 

Self-Assembled Supramolecules,” J. Phys. Chem. B 112 (43), 13483 

(2008). (CHRNS)

Thomas, E.L., Wong-Ng, W., Phelan, D., Millican, J.N., “Thermopower of 

Co-Doped FeSe,” J. Appl. Phys. 105 (7), 073906 (2009).

Thomas, J.J., Allen, A.J., Jennings, H.M., “Structural Changes to the 

Calcium–Silicate–Hydrate Gel Phase of Hydrated Cement with 

Age, Drying, and Resaturation,” J. Am. Chem. Soc. 91 (10), 3362 

(2008).

Thomas, J.J., Jennings, H.M., Chen, J.J., “Influence of Nucleation Seeding 

on the Hydration Mechanisms of Tricalcium Silicate and Cement,” J. 

Phys. Chem. C 113 (11), 4327 (2009). (CHRNS)

Thompson, S.M., Ma, H.B., Winholtz, R.A., Wilson, C., “Experimental 

Investigation of Miniature Three-Dimensional Flat-Plate Oscillating 

Heat Pipe,” J. Heat Transfer 131 (4), 043210 (2009).

Tian, W., Li, J., Lynn, J.W., Zarestky, J.L., Vaknin, D., “Spin Dynamics in 

the Magnetoelectric Effect Compound LiCoPO4,” Phys. Rev. B 78

(18), 184429 (2008). (CHRNS)

Tomlin, B.E., Zeisler, R., “Improvements in Determinations Using the 

Cu-64 Annihilation Gamma-Rays,” Appl. Radiat. Isot., in press.

Tranquada, J.M., Gu, G.D., Hücker, M., Jie, Q., Kang, H.J., Klingeler, 

R., Li, Q., Tristan, N., Wen, J.S., Xu, G.Y., Xu, Z.J., Zhou, J., 

Zimmermann, M.V., “Evidence for Unusual Superconducting 

Correlations Coexisting with Stripe Order in La1.875Ba0.125CuO4,” 

Phys. Rev. B 78 (17), 174529 (2008). (CHRNS)

Tucker, I., Penfold, J., Thomas, R.K., Grillo, I., Mildner, D.F.R., Barker, 

J.G., “Self-Assembly in Complex Mixed Surfactant Solutions: The 

Impact of Dodecyl Triethylene Glycol on Dihexadecyl Dimethyl 

Ammonium Bromide,” Langmuir 24 (18), 10089 (2008).

Tucker, I., Penfold, J., Thomas, R.K., Grillo, I., Mildner, D.F.R., Barker, 

J.G., “Self-Assembly in Mixed Dialkyl Chain Cationic−Nonionic 

Surfactant Mixtures: Dihexadecyldimethyl Ammonium Bromide−

Monododecyl Hexaethylene Glycol (Monododecyl Dodecaethylene 

Glycol) Mixtures,” Langmuir 24 (15), 7674 (2008).

Udby, L., Andersen, N.H., Chou, F.C., Christensen, N.B., Emery, S.B., 

Lefmann, K., Lynn, J.W., Mohottala, H.E., Niedermayer, C., Wells, 

B.O., “Magnetic Ordering in Electronically Phase Separated La2−

xSrxCuO4+y: Neutron Diffraction Experiments,” Phys. Rev. B 80 (1), 

014505 (2009). (CHRNS)

Udovic, T.J., Huang, Q., Santoro, A., Rush, J.J., “The Nature of Deuterium 

Arrangements in YD3 and Other Rare-Earth Trideuterides,” Z. 

Kristallogr. 223 (10), 697 (2008).

Valincius, G., Heinrich, F., Budvytyte, R., Vanderah, D.J., McGillivray, 

D.J., Sokolov, Y., Hall, J.E., Lösche, M., “Soluble Amyloid β 

Oligomers Affect Dielectric Membrane Properties by Bilayer 

Insertion and Domain Formation: Implications for Cell Toxicity,” 

Biophys. J. 95 (10), 4845 (2008).

Vandoolaeghe, P., Campbell, R.A., Reenie, A.R., Nylander, T., 

“Adsorption of Intact Cubic Liquid Crystalline Nanoparticles on 

Hydrophilic Surfaces: Lateral Organization, Interfacial Stability, 

Layer Structure, and Interaction Mechanism,” J. Phys. Chem. C 113

(11), 4483 (2009).

Vandoolaeghe, P., Rennie, A.R., Campbell, R.A., Nylander, T., “Neutron 

Reflectivity Studies of the Interaction of Cubic-Phase Nanoparticles 

with Phospholipid Bilayers of Different Coverage,” Langmuir 25

(7), 4009 (2009).

VanOudenhove, J., Anderson, E., Krueger, S., Cole, J.L., “Analysis of PKR 

Structure by Small-Angle Scattering,” J. Mol. Biol. 387 (4), 910 

(2009). (CHRNS)

Verruto, V.J., Kilpatrick, P.K., “Water-in-Model Oil Emulsions Studied 

by Small-Angle Neutron Scattering: Interfacial Film Thickness and 

Composition,” Langmuir 24 (22), 12807 (2008). (CHRNS)

Wang, B., Tchessalov, S., Cicerone, M.T., Warne, N.W., Pikal, M.J., 

“Impact of Sucrose Level on Storage Stability of Proteins in FreezeDried Solids: II. Correlation of Aggregation Rate with Protein 

Structure and Molecular Mobility,” J. Pharm. Sci., in press. (CHRNS)

Wang, J.Y., Chen, W., Russell, T.P., “Ion-Complexation-Induced Changes 

in the Interaction Parameter and the Chain Conformation of PS-bPMMA Copolymers,” Macromol. 41, 4904 (2008). (CHRNS)

Weber, A.Z., Hickner, M.A., “Modeling and High-Resolution-Imaging 

Studies of Water-Content Profiles in a Polymer-Electrolyte-FuelCell Membrane-Electrode Assembly,” Electrochim. Acta 53 (26), 

7668 (2008).

Wen, J., Xu, G., Gu, G., Shapiro, S.M., “Magnetic-Field Control of Charge 

Structures in the Magnetically Disordered Phase of Multiferroic 

LuFe2O4,” Phys. Rev. B 80 (2), 020403 (2009).

Wen, J., Xu, G., Stock, C., Gehring, P.M., “Response of Polar Nanoregions 

in 68%Pb(Mg1/3Nb2/3)O3-32%PbTiO3 to a [001] Electric Field,” 

Appl. Phys. Lett. 93 (8), 082901 (2008).

Wen, J., Xu, G., Stock, C., Gehring, P.M., Zhong, Z., Boatner, L.A., 

Venturini, E.L., Samara, G.A., “Effect of Local Dipole Moments on 

the Structure and Lattice Dynamics of K0.98Li0.02TaO3,” Phys. Rev. B 

78 (14), 144202 (2008). (chrns)
78

Wen, J., Xu, Z., Xu, G., Tranquada, J.M., Gu, G., Chang, S., Kang,

H.J., “Magnetic Field Induced Enhancement of Spin-Order 

Peak Intensity in La1.875Ba0.125CuO4,” Phys. Rev. B 78 (21),

212506 (2008). (chrns)

West, D.V., Huang, Q., Zandbergen, H.W., McQueen, T.M., Cava, 

R.J., “Structural Disorder, Octahedral Coordination, and

2-Dimensional Ferromagnetism in Anhydrous Alums,” J.

Solid State Chem. 181 (10), 2768 (2008).

West, D.V., McQueen, T.M., Huang, Q., Cava, R.J., “Structural

and Magnetic Properties of Pyrochlore Solid Solutions 

(Y,Lu)2Ti2-x(Nb,Ta)xO7±y,” J. Solid State Chem. y 181 (8),

1753 (2008).

West, D.V., McQueen, T.M., Posen, I.D., Ke, X., Huang, Q., 

Zandbergen, H.W., Williams, A.J., Schiffer, P., Cava, 

R.J., “The A2+Mn5(SO4)6 Family of Triangular Lattice, 

Ferrimagnetic Sulfates,” J. Solid State Chem. 182 (6), 1343

(2009).

West, D.V., Posen, I.D., Huang, Q., Zandbergen, H.W.,

McQueen, T.M., Cava, R.J., “PbMn(SO4)2: A New Chiral

Antiferromagnet,” J. Solid State Chem., in press.

White, J.S., Hinkov, V., Heslop, R.W., Lycett, R.J., Forgan, 

E.M., Bowell, C., Strässle, S., Abrahamsen, A.B., Laver, M., 

Dewhurst, C.D., Kohlbrecher, J., Gavilano, J.L., Mesot, J., 

Keimer, B., Erb, A., “Fermi Surface and Order Parameter

Driven Vortex Lattice Structure Transitions in Twin-Free

YBa2Cu3O7,” Phys. Rev. Lett. 102 (9), 097001 (2009).

Whitten, A.E., Jeffries, C.M., Harris, S.P., Trewhella, J., “Cardiac 

Myosin-Binding Protein C Decorates F-Actin: Implications

for Cardiac Function,” Proc. Natl. Acad. Sci. USA, 105 (47),

18360 (2008). (chrns)

Wong-Ng, W., Yang, Z., Hu, Y.F., Huang, Q., Lowhorn, N., Otani, 

M., Kaduk, J.A., Li, Q., “Thermoelectric and Structural

Characterization of Ba2Ho(Cu3-xCox)O6+y,” J. Appl. Phys. y

105 (6), 063706 (2009).

Wu, H., “Strategies for the Improvement of the Hydrogen Storage

Properties of Metal Hydride Materials,” Chem. Phys. Chem.

9 (15), 2157 (2008).

Wu, H., Zhou, W., Udovic, T.J., Rush, J.J., Yildirim, T., “Crystal

Chemistry and Dehydrogenation Rehydrogenation

Properties of Perovskite Hydrides RbMgH3 and RbCaH3,” J.

Phys. Chem. C, in press.

Wu, H., Zhou, W., Wang, K., Udovic, T.J., Rush, J.J., Yildirim, 

T., Bendersky, L.A., Gross, A.F., Van Atta, S.L., Vajo, J.J., 

Pinkerton, F.E., Meyer, M.S., “Size Effects on the Hydrogen

Storage Properties of the Nanoscaffolded Li3BN2H8,”

Nanotech. 20, 204002 (2009).

Wu, H., Zhou, W., Yildirim, T., “Alkali and Alkaline-Earth Metal

Amidoboranes: Structure, Crystal Chemistry, and Hydrogen

Storage Properties,” J. Am. Chem. Soc. 130 (44), 14834

(2008).

Wu, H., Zhou, W., Yildirim, T., “High-Capacity Methane Storage in

Metal−Organic Frameworks M2(dhtp): The Important Role of

Open Metal Sites,” J. Am. Chem. Soc. 131 (13), 4995 (2009).

Wu, H., Zhou, W., Yildirim, T., “Methane Sorption in Nanoporous 

Metal−Organic Frameworks and First-Order Phase Transition of 

Confined Methane,” J. Phys. Chem. C 113 (7), 3029 (2009).

Wu, W., Kiryukhin, V., Noh, H.J., Ko, K.-T., Park, J.H., Ratcliff, W.,

Sharma, P.A., Harrison, N., Choi, Y.J., Horime, Y., Lee, S., Park, S., 

Yi, H.T., Zhang, C.L., Cheong, S.W., “Formation of Pancakelike 

Ising Domains and Giant Magnetic Coercivity in Ferrimagnetic 

LuFe2O4,” Phys. Rev. Lett. 101 (13), 135203 (2008).

Wu, Y., Yu, B., Jackson, A., Zha, W., Lee, L.J., Wyslouzil, B.E., “Coaxial

Electrohydrodynamic Spraying: A Novel One-Step Technique

to Prepare Oligodeoxynucleotide Encapsulated Lipoplex

Nanoparticles,” Mol. Pharmaceutics, in press.

Xue, M., Liu, Y., Schaffino, R.M., Xiang, S., Zhao, X., Zhu, G.S., Qiu, 

S.L., Chen, B., “New Prototype Isoreticular Metal−Organic 

Framework Zn4O(FMA)3 for Gas Storage,” Inorg. Chem. 48 (11),

4649 (2009).

Yager, K.G., Berry, B.C., Page, K., Patton, D., Karim, A., Amis, E.J., 

“Disordered Nanoparticle Interfaces for Directed Self-Assembly,”

Soft Matter 5 (3), 622 (2009).

Yamada, N.L., Endo, H., Osaka, N., Kawabata, Y., Nagao, M., Takeda, 

T., Seto, H., Shibayama, M., “Detector Area Expansion at iNSE 

Neutron Spin Echo Spectrometer,” Physica B, in press.

Yamaura, K., Huang, Q., Takayama-Muromachi, E., “Superconductivity 

and Structure of η-Mo3C2,” Physica C 468 (15), 1135 (2008).

Yang, H., Shin, K., Tae, G., Satija, S.K., “Structure of a Monolayer of 

Poly(ethylene glycol) End-Capped with a Fluoroalkyl Group and

its Relationship with Protein Adsorption at the Aqueous Interface,” 

Soft Matter, in press.

Ye, F., Ren, Y., Fernandez-Baca, J.A., Mook, H.A., Lynn, J.W., Chaudhury,

R.P., Wang, Y.Q., Lorenz, B., Chu, C.W., “Magnetic Switching and 

Phase Competition in the Multiferroic Antiferromagnet

Mn1−xFexWO4,” Phys. Rev. B 78 (19), 193101 (2008).

Yeon, S.H., Osswald, S., Gogotsi, Y., Singer, J.P., Simmons, J.M., Fischer, 

J.E., Lillo-Rodenas, M.A., Linares-Solano, A., “Enhanced Methane

Storage of Chemically and Physically Activated Carbide-Derived 

Carbon,” J. Power Sources 191, 560 (2009).

Yi, Z., Nagao, M., Bossev, D.P., “Bending Elasticity of Saturated and

Monounsaturated Phospholipid Membranes Studied by the

Neutron Spin Echo Technique,” J. Phys.: Condens. Mat. 21 (15),

155104 (2009). (CHRNS)

Yildirim, T., “Frustrated Magnetic Interactions, Giant Magneto-Elastic

Coupling, and Magnetic Phonons in Iron-Pnictides,” Physica C 469

(9-12), 425 (2009).

Publications
NCNR 2009 Accomplishments and Opportunities 79

Yildirim, T., “Origin of the 150-K Anomaly in LaFeAsO: Competing 

Antiferromagnetic Interactions, Frustration, and a Structural Phase 

Transition,” Phys. Rev. Lett. 101 (5), 057010 (2008).

Yildirim, T., “Strong Coupling of the Fe-Spin State and the As-As 

Hybridization in Iron-Pnictide Superconductors from FirstPrinciple Calculations,” Phys. Rev. Lett. 102 (3), 037003 (2009).

Yildirim, T., Vergara, L.I., Íñiguez, J., Musfeldt, J.L., Harris, A.B., Rogado, 

N., Cava, R.J., Yen, F., Chaudhury, R.P., Lorenz, B., “Phonons and 

Magnetoelectric Interactions in Ni3V2O8,” J. Phys.: Condens. Mat. 

20 (43), 434214 (2008).

Yoonessi, M., Seikel, E., Pender, M.J., “Characterization and Modeling of 

Stable Colloids of Organically Surface Tailored Gold Nanoparticle 

Liquids,” Langmuir 25 (6), 3369 (2009).

Yousufuddin, M., Her, J.-H., Zhou, W., Jalisatgi, S.S., Udovic, T.J., 

“Crystal Structure, Neutron Vibrational Spectroscopy, and DFT 

Calculations of Li2B12H12 · 4H2O,” Inorg. Chim. Acta 362 (9), 3155 

(2009).

Yun, S.I., Gadd, G.E., Lo, V., Gauthier, M., Munam, A., “TemperatureResponsive Supramolecular Assembly and Morphology of 

Arborescent Copolymer Micelles with a Solvophilic Core−

Solvophobic Shell Structure,” Macromol. 41 (19), 7166 (2008). 

(chrns)

Zeisler, R., Greenberg, R.R., Mackey, E.A., Murphy, K.E., Spatz, R.O., 

Tomlin, B.E., “Challenges and Successes in the Use of Neutron 

Activation Analysis Procedures for Value Assignment of Animal 

Serum and Bovine Liver Standard Reference Materials”, J. Radioanal. 

Nucl. Chem. 281 (1), 11 (2009).

Zeisler, R., Heller-Zeisler, S., Ünlü, K., Williamson, C., “Current 

Status, Trends, and Needs in Radiochemical Education: The US 

and Abroad,” in “8th International Conference on Methods and 

Applications of Radioanalytical Chemistry: MARC-VIII,” edited 

by Zeisler, R., Ünlü, K., Heller-Zeisler, S., (AIP Conf. Proc.), in 

press.

Zeisler, R., James, W.D., Mackey, E.A., Spatz, R.O., Greenberg, R.R., 

“NAA Characterization of the New Bovine Liver SRM,” J. 

Radioanal. Nucl. Chem. 278 (3), 783 (2008).

Zeisler, R., Lindstrom, R.M., Tomlin, B.E., “Development of Quality 

Assessment Tools for Activation Analysis Software,” Trans. Am. 

Nucl. Soc. 99, 59 (2008).

Zeisler, R., Paul, R.L., Spatz, R.O., “Reproducible Elemental Analyses of 

Single-Walled Carbon Nanotubes by Neutron Activation Analysis,” 

Trans. Am. Nucl. Soc. 100, 247 (2009).

Zhang, X., Berry, B.C., Yager, K.G., Kim, S., Jones, R.L., Satija, S., Pickel, 

D.L., Douglas, J.F., Karim, A., “Surface Morphology Diagram for 

Cylinder-Forming Block Copolymer Thin Films,” ACS Nano 2

(11), 2331 (2008).

Zhang, Y., Lagi, M., Liu, D., Mallamace, F., Fratini, E., Baglioni, P., 

Mamontov, E., Hagen, M., Chen, S.H., “Observation of HighTemperature Dynamic Crossover in Protein Hydration Water and 

its Relation to Reversible Denaturation of Lysozyme,” J. Chem. Phys. 

130 (13), 135101 (2009).

Zhao, J., Huang, Q., de la Cruz, C., Li, S., Lynn, J.W., Chen, Y., Green, 

M.A., Chen, G.F., Li, G., Li, Z., Luo, J.L., Wang, N.L., Dai, P., 

“Structural and Magnetic Phase Diagram of CeFeAsO1-xFx and its 

Relation to High-Temperature Superconductivity,” Nat. Mater. 7, 

953 (2008).

Zhao, J., Huang, Q., de la Cruz, C., Lynn, J.W., Lumsden, M.D., Ren, 

Z.A., Yang, J., Shen, X., Dong, X., Zhao, Z., Dai, P., “Lattice and 

Magnetic Structures of PrFeAsO, PrFeAsO0.85F0.15, and PrFeAsO0.85,” 

Phys. Rev. B 78 (13), 132504 (2008).

Zhao, J., Ratcliff, W., Lynn, J.W., Chen, G.F., Luo, J.L., Wang, N.L., Hu, J., 

Dai, P., “Spin and Lattice Structures of Single-Crystalline SrFe2As2,” 

Phys. Rev. B 78 (14), 140504 (2008).

Zhao, J., Yao, D.X., Li, S., Hong, T., Chen, Y., Chang, S., Ratcliff, W., 

Lynn, J.W., Mook, H.A., Chen, G.F., Luo, J.L., Wang, N.L., Carlson, 

E.W., Hu, J., Dai, P., “Low Energy Spin Waves and Magnetic 

Interactions in SrFe2As2,” Phys. Rev. Lett. 101 (16), 167203 (2008). 

(chrns)

Zhou, H.D., Wiebe, C.R., Balicas, L., Yo, Y.J., Qiu, Y., Copley, J.R.D., 

Gardner, J.S., “Intrinsic Spin-Disordered Ground State of the Ising 

Garnet Ho3Ga5O12,” Phys. Rev. B 78 (14), 140406 (2008). (CHRNS)

Zhou, H.D., Wiebe, C.R., Janik, J.A., Balicas, L., Yo, Y.J., Qiu, Y., Copley, 

J.R.D., Gardner, J.S., “Dynamic Spin Ice: Pr2Sn2O7,” Phys. Rev. Lett. 

101 (22), 227204 (2008). (chrns)

Zhou, H.D., Wiebe, C.R., Jo, Y.J., Balicas, L., Urbano, R.R., Lumata, 

L.L., Brooks, J.S., Kuhns, P.L., Reyes, A.P., Qiu, Y., Copley, J.R.D., 

Gardner, J.S., “Chemical Pressure Induced Spin Freezing Phase 

Transition in Kagomé Pr Langasites,” Phys. Rev. Lett. 102 (6), 

067203 (2009). (chrns)

Zhou, H.D., Wiebe, C.R., Yo, Y.J., Balicas, L., Takano, Y., Case, M.J., 

Qiu, Y., Copley, J.R.D., Gardner, J.S., “Nanoscale Freezing of the 

2D Spin Liquid Pr3Ga5SiO14,” Meas. Sci. Technol. 19 (3), 34023 

(2008). (chrns)

Zhou, W., Wu, H., Yildirim, T., Simpson, J.R., Hight Walker, A.R., 

“Origin of the Exceptional Negative Thermal Expansion in 

Metal-Organic Framework-5 Zn4O(1,4-benzenedicarboxylate)3,” 

Phys. Rev. B 78 (5), 054114 (2008). (chrns)

Zhou, W., Wu, H., Udovic, T.J., Rush, J.J., Yildirim, T., “Quasi-Free 

Methyl Rotation in Zeolitic Imidazolate Framework-8,” J. Phys. 

Chem. A 112 (49), 12602 (2008). (chrns)

Zhou, W., Wu, H., Yildirim, T., “Enhanced H2 Adsorption in 

Isostructural Metal−Organic Frameworks with Open Metal Sites: 

Strong Dependence of the Binding Strength on Metal Ions,” J. Am. 

Chem. Soc. 130 (46), 15268 (2008).
80Instruments and Contacts

Instruments and Contacts: (name, tel. 301-975-xxxx, email)

High Resolution Powder Diffractometer (BT-1):

r +VEZ4UBMJDL

Kudith.stalick@nist.gov

r 2JOH[IFO)VBOH

Ring.huang.@nist.gov

r .BSL(SFFO

NBSL.green@nist.gov

Residual Stress Diffractometer (BT-8):

r ăPNBT(OBFVQFM)FSPME

Ug-h@nist.gov

30-m SANS Instrument (NG-7):

r :VO-JV

ZVOMJV!OJTUHPW

r 1aul Butler, 2028, paul.butler@nist.gov

r Jeff Krzywon, 6650, jkrzywon@nist.gov

30-m SANS Instrument (NG-3) (CHRNS):

r Boualem Hammouda, 3961, hammouda@nist.gov

r Steve Kline, 6243, steven.kline@nist.gov

r Susan Krueger, 6734, susan.krueger@nist.gov

r $FESJD(BHOPO

Dedric.gagnon@nist.gov

USANS, Perfect Crystal SANS (BT-5) (CHRNS):

r "OESFX+BDLTPO

Bndrew.jackson@nist.gov

r %BWJE.JMEOFS

EBWJENJMEOFS!OJTUHPW

r Paul Butler, 2028, paul.butler@nist.gov

Reflectometer, Vertical Sample, Polarized Beam Option (NG-1):

#SJBO,JSCZ

Crian.kirby@nist.gov

r +VMJF#PSDIFST

Kulie.borchers@nist.gov

r $IVDL.BKLS[BL

Dmajkrzak@nist.gov

AND/R, Advanced Neutron Diffractometer/Reflectometer (NG-1):

r +PF%VSB

Koseph.dura@nist.gov

r #SJBO.BSBOWJMMF

CSJBONBSBOWJMMF!OJTUHPW

Reflectometer, Horizontal Sample (NG-7):

r 4VTIJM4BUJKB

Tatija@nist.gov

r #VMFOU"LHVO

Culent.akgun@nist.gov

Double-focusing Triple Axis Spectrometer (BT-7):

r 4POHYVF$IJ

TPOHYVFDIJ!OJTUHPW

r +FĈ-ZOO

Keff.lynn@nist.gov

Triple-axis Spectrometer (BT-9):

r 8JMMJBN3BUDMJĈ

Xilliam.ratcliff@nist.gov

r 3PTT&SXJO

Serwin@nist.gov

r +FĈ-ZOO

Keff.lynn@nist.gov

SPINS, Spin-polarized Triple-axis Spectrometer (NG-5) (CHRNS):

r 4VOH$IBOH

Tung.chang@nist.gov

r %FFQBL4JOHI

EFFQBLTJOHI!OJTUHPW

MACS, Multi-Analyzer Crystal Spectrometer (NG-0)

r +PTF3PESJHVF[

Kose.rodriguez@nist.gov

r $PMMJO#SPIPMN

DPMMJOCSPIPMN!OJTUHPv

FANS, Filter-analyzer Neutron Spectrometer (BT-4):

r 5FSSZ6EPWJD

UVdovic@nist.gov

r +VTDFMJOP-FÈP

Kuscelino.leao@nist.gov

DCS, Disk-chopper Time-of-flight Spectrometer (NG-4) (CHRNS):

r +PIO$PQMFZ

Kcopley@nist.gov

r :JNJOH2JV

Ziming.qiu@nist.gov

r $SBJH#SPXO

Draig.brown@nist.gov

HFBS, High-flux Backscattering Spectrometer (NG-2) (CHRNS):

r .BEIVTVEBO5ZBHJ

Ntyagi@nist.gov

r 5JN+FOLJOT

Uimothy.jenkins@nist.gov

NSE, Neutron Spin Echo Spectrometer (NG-5) (CHRNS):

r "OUPOJP'BSBPOF

 Bntonio.faraone@nist.gov

r +BTPO(BSEOFS

Kason.gardner@nist.gov

r .JDIJ/BHBP

Nichihiro.nagao@nist.gov

Cold Prompt-gamma Neutron Activation Analysis (NG-7):

r 3JDL1BVM

Spaul@nist.gov

Thermal Prompt-gamma Neutron Activation Analysis (VT-5): 

r -J[.BDLFZ

Miz.mackey@nist.gov

Other Activation Analysis Facilities: 

r (SFH%PXOJOH

Hregory.downing@nist.gov

Cold Neutron Depth Profiling (NG-1):

r (SFH%PXOJOH

Hregory.downing@nist.gov

Neutron Imaging Station (BT-2):

r %BWJE+BDPCTPO

Eavid.jacobson@nist.gov

r %BO)VTTFZ

Eaniel.hussey@nist.gov

r .VIBNNBE"SJG

Nuhammad.arif@nist.gov

Neutron Interferometer (NG-7):

r .VIBNNBE"SJG

Nuhammad.arif@nist.gov

r %BWF+BDPCTPO

Eavid.jacobson@nist.gov

r %BO)VTTFZ

Eaniel.hussey@nist.gov

Fundamental Neutron Physics Station (NG-6): 

r /(.4DPUU%FXFZ

Ndewey@nist.gov

r /(61JFUFS.VNN

Qieter.mumm@nist.gov

r /(+FĈ/JDP

Oico@nist.gov

Theory and Modeling:

r 5BOFS:JMEJSJN

Uaner@nist.gov

r +PTFQI$VSUJT

Koseph.curtis@nist.gov

Sample Environment: 

r +VMJB4DIFSTDIMJHU

KVMJBTDIFSTDIMJHU!OJTUHPW

r +VTDFMJOP-FÈP

Kuscelino.leao@nist.gov

Instruments and Contacts
NIST CENTER FOR NEUTRON RESEARCH CONTACTS

Copies of annual reports, facility information, user information,

And research proposal guidelines are available electronically.

Please vist our website: http://www.ncnr.nist.gov

For a paper copy of this report:

Ron Cappelletti

301-975-6221

ron.cappelletti@nist.gov

For general information on the facility:

Rob Dimeo

301-975-6210

robert.dimeo@nist.gov

Dan Neumann

301-975-5252

dan.neumann@nist.gov

For information on visiting the

facility and/or user access questions:

User Office:

Mary Ann FitzGerald

301-975-8200

maryann.fitzgerald@nist.gov

For information on performing

research at the facility:

Bill Kamitakahara

301-975-6878

william.kamitakahara@nist.gov

Facility address:

NIST Center for Neutron Research

Nationial Institute of Standards and Technology

100 Bureau Drive, Mail Stop 6100

Gaithersburg, MD 20899-6100

USA