THE CNST NEWS
 

SPRING/SUMMER 2015 

ELECTRON WHISPERING GALLERIES 

CREATED IN GRAPHENE 

INSIDE 

A SPEED BUMP FOR REGULATING HIGH-SPEED PLASMONIC DATA FLOW 

DOUBLE VISION: SEE THE NANOSCALE ‘FOREST’ AND ‘TREES’ SIMULTANEOUSLY 

IMAGING ANODE OXIDATION IN SOLID STATE BATTERIES 

WWW.NIST.GOV/CNST 
 

 

 

 

IN THIS ISSUE
 

From the Director | 2 

Double Vision: NIST Technique 

Offers Way to See the 

Nanoscale ‘Forest’ and ‘Tree’ 

Simultaneously | 3 

First Whispering Gallery for 

Graphene Electrons | 4 

Good Vibrations: Measuring 

Phonons in Graphene | 5 

Oxidation on Aluminum Anodes 

Degrades Performance of 

Solid State Batteries | 6 

Mind the Gap: Nanoscale 

Speed Bump Could Regulate 

Plasmons for High-Speed 

Data Flow | 7 

New Atomic Layer Deposition 

Technique Coats High-Aspect 

Ratio Nanoporous Membranes 

with Platinum | 8 

Magneto-Optical Technique 

Measures Fields from Individual 

Magnetic Nanoparticles | 8 

CNST’s Vladimir Aksyuk 

Elected Fellow of the American 

Physical Society | 9 

Learning Cleanroom Skills 

through Hands-On Experience | 9 

Robert Celotta, Daniel Pierce, 

and John Unguris share 2015 

Keithley Award for Advances 

in Measurement Science | 10 

Recent Publications by 

CNST Staff Researchers | 11 

Organizational News: 

CNST to host Workshop on 

Advancing Nanoparticle 

Manufacturing | 12 

EDITOR | 

KRISTEN DILL 

CONTRIBUTORS | 

MARK ESSER 

ALEXANDER LIDDLE 

ROBERT RUDNITSKY 

GRAPHIC DESIGN | 

KRISTEN DILL 

DISCLAIMER | Certain commercial equipment, 

and software, are identified in this documentation 

to describe the subject adequately. Such 

identification does not imply recommendation 

or endorsement by the National Institute of 

Standards and Technology, nor does it imply that 

the equipment identified is necessarily the best 

available for the purpose. 

FROM THE 

DIRECTOR 

I

f you’ve been following the CNST News for any period of time, you 

probably understand that the Center for Nanoscale Science and 

Technology is a user facility with a unique design. It has two parts, 

the NanoFab and the NanoLab, with the NanoFab offering easy access 

to a full set of commercial state-of-the-art fabrication and measurement technology and the NanoLab 

offering potential solutions to problems that reach beyond current, commercial measurement or fabrication 

solutions. So, it is natural to think of the NanoFab as the “go to” destination for a nanotech measurement 

requirement. However, a rather broad spectrum of nanotechnology measurement solutions exist within the 

NanoLab and are available for use through collaboration. This issue illustrates three of those opportunities. 

The research described on page three makes use of a unique instrument, an Environmental Scanning 

Transmission Electron Microscope (ESTEM) with Raman spectroscopy incorporated into the heart of the 

microscope by the CNST. It allows one to focus (literally) on the atomic scale to determine stoichiometry 

and structure while using spectroscopy to monitor both the chemistry and the temperature — all at the 

temperatures and pressures typical of the catalytic reactions we want to better understand. 

On page four, a probe is described that uses electrons in a very different way. Here the CNST’s low 

temperature scanning tunneling microscope is used to form a circular potential barrier on a graphene 

surface. This barrier constrains the electrons to propagate around its edge in a so-called “whispering 

gallery mode”, emulating the phenomena that allows sound to propagate long distances within the dome 

of St. Paul’s Cathedral in London and adding a new tool to our kit for controlling and focusing electrons on 

surfaces. 

Finally, the article on page six explains how a variety of tools, including scanning and Auger electron 

microscopy and photoelectron spectroscopy, are used to explore what’s happening beneath the surface 

in solid-state batteries. The changing terrain those ions see as they move nanoscale distances accounts 

for the degradation of the battery with use. By facilitating access to nanoscale techniques and tools, such 

as those described on page six, we hope, working with our interested users, to better understand how the 

changing structure affects performance and ultimately play a role in extending battery lifetimes. 

If you have a challenging nanofabrication or nanoscale measurement problem, you may want to see 

whether ongoing research in CNST’s NanoLab could help. To see if we are already working on your problem 

or might have the necessary expertise to help solve it, check the CNST webpages or look in the NanoLab 

section of the CNST brochure. 

Robert Celotta 

2 
3 

 

DOUBLE VISION: NIST TECHNIQUE OFFERS WAY TO SEE THE NANOSCALE 

‘FOREST’ AND ‘TREE’ SIMULTANEOUSLY 

Aclose up view of an individual tree won’t 

tell you much about what’s going on in the 

forest. The same goes for studying collections 

of nanoparticles. What is happening on one 

nanoparticle may not be indicative of what’s going 

on with the group as a whole. In fact, just as 

shining a light on a single plant to observe it will 

lead to an overestimate of the average growth rate, 

the electron beam that you shine on nanoparticles 

to see them may actually affect the reaction 

processes, giving a skewed reading. 

To correct for this experimental myopia, 

researchers at the National Institute of Standards 

and Technology (NIST) have developed a relatively 

simple setup that makes it possible for scientists 

to image individual nanoscale features and collect 

microscale (nano x1,000) chemical information 

simultaneously. Their approach combines two 

powerful analysis tools, environmental scanning 

transmission electron microscopy (ESTEM), a 

variation on traditional electron microscopes 

that enables researchers to view a specimen in a 

reactive gas environment—i.e. not in a vacuum— 

and Raman spectroscopy, which uses light 

interactions to identify molecular structures from 

their characteristic vibrations. Their description 

of the development of the new imaging setup 

appeared in the journal Ultramicroscopy. 

Having such a combined close-up and wide-angle 

view of nanoparticle behavior, allows researchers 

to understand both what the nanoparticles are 

doing and how they are doing it. It also ensures that 

researchers have enough information to make sure 

they are not being fooled by any unusual effects 

that could be caused by the electron beam. Such 

comprehensive and reliable data would be useful 

to scientists working in a broad range of research 

areas from nanotechnology to pharmaceuticals and 

biotechnology. 

The team’s technique consists of inserting a tiny, 

diamond-machined, parabolic mirror attached 

to a hollow rod below the sample they wish to 

study. The parabolic mirror serves two purposes. 

It focuses the light from a source, such as a laser, 

outside the ESTEM, that passes through the hollow 

rod, onto the sample to excite it and collects the 

sample’s response to that excitation, i.e. the 

Raman spectra, for analysis. The Raman signal 

Image of a multi-wall CNT growing from a nanoscale catalyst particle. Inset: Plot of the Raman spectrum as a function of time 

during carbon nanotube growth at 625°C in a low pressure (10-3 Pa) atmosphere of acetylene (C2

H2). After an initial nucleation 

period, the signal from the G+ band, characteristic of the graphene that makes up the walls of the carbon nanotubes, appears 

and rises rapidly, before increasing at a constant rate. This indicates that, once they have formed, the nanotubes grow at a 

constant rate. 

comes from an area about a million times bigger 

than the area that can be seen at the atomic scale 

with the electron beam. That way, the close-up 

data from the images can be compared with the 

“wide-angle” view of the chemistry to make sure it 

all matches up correctly. 

As a bonus, according to NIST researcher Renu 

Sharma, measuring the shifts in Raman signal 

energy also enables them to measure the local 

temperature of a sample region – which is normally 

very hard to do – letting them make accurate 

measurements of the chemical kinetics. 

“Most importantly, the ESTEM-Raman combination 

will provide us with the unique opportunity to study 

gas and temperature effects on technologically 

important nanostructures,” says Sharma. “For 

example, the morphology or make-up of nanoscale 

structures may change as function of temperature, 

environment and time, thus degrading their 

efficiency or performance. Being able to see 

exactly what’s going on may enable the production 

of better, longer-lasting nanostructures.” 

Finally, while the technique was initially developed 

to enable Raman spectroscopy of the sample, the 

parabolic mirror can also collect light generated 

when the electron beam interacts with the sample. 

This light contains masses of useful information 

on things like the energy levels in nanoscale 

semiconductor structures and the surface plasmons 

on metal nanoparticles. All of this data can be 

used to help understand the essential link between 

structure and properties on the nanoscale. 

While the system was developed for use with an 

ESTEM, the vibrational and optical spectroscopy 

elements the group developed can be adapted for 

any transmission electron microscope column. 

Vibrational and optical spectroscopies integrated with environmental transmission electron microscopy, M. Picher, S. Mazzucco, S. Blankenship, and R. Sharma, Ultramicroscopy 150, 10–15 (2015). 
FIRST WHISPERING GALLERY FOR GRAPHENE ELECTRONS
 

ACNST-led international research group has 

developed a technique for creating nanoscale 

whispering galleries for electrons in graphene. The 

development opens the way to building devices 

that focus and amplify electrons just as lenses 

focus light and resonators (like the body of a guitar) 

amplify sound. 

In some structures, such as the dome in St. Paul’s 

Cathedral in London, a person standing near a 

curved wall can hear the faintest sound made 

along any other part of that wall. This phenomenon, 

called a whispering gallery, occurs because 

sound waves reflect along a curved surface and 

re-inforce themselves for certain frequencies to 

create the whispering gallery modes. Using this 

same principle, scientists have built whispering 

galleries for light waves as well, and whispering 

galleries are found in applications ranging from 

sensing, spectroscopy and communications to the 

generation of laser frequency combs. 

“The cool thing is that we made a nanometer 

scale electronic analogue of a classical wave 

effect,” said NIST Fellow Joe Stroscio, who led 

the research team. “These whispering galleries are 

unlike anything you see in any other electron based 

system, and that’s really exciting.” 

Ever since graphene, a single layer of carbon atoms 

arranged in a honeycomb lattice, was first created 

in 2004, the material has impressed researchers 

with its strength, ability to conduct electricity and 

heat and many interesting optical, magnetic and 

chemical properties. 

However, early studies of the behavior of electrons 

in graphene were hampered by defects in the 

material. As the manufacture of clean and nearperfect graphene becomes more routine, scientists 

are beginning to uncover its full potential. 

When moving electrons encounter a potential 

barrier in conventional semiconductors, it takes 

an increase in energy for the electron to continue 

flowing. As a result, they are often reflected, just as 

one would expect from a ball-like particle. 

However, because electrons can sometimes behave 

like a wave, there is a calculable chance that they 

will ignore the barrier altogether, a phenomenon 

called tunneling. Due to the light-like properties 

Using the voltage from a scanning tunneling microscope tip (top) to push graphene electrons out of a nanoscale area, the 

researchers created a whispering gallery (centered on the dark blue area on the graphene surface), which is like a circular wall 

of mirrors to the electron. 

of graphene electrons, they can pass through 

unimpeded—no matter how high the barrier—if 

they hit the barrier head on. This tendency to tunnel 

makes it hard to steer electrons in graphene. 

Enter the graphene electron whispering gallery. 

To create a whispering gallery in graphene, the 

team first enriched the graphene with electrons 

from a conductive plate mounted below it. With 

the graphene now crackling with electrons, the 

research team used the voltage from a scanning 

tunneling microscope (STM) to push some of them 

out of a nanoscale-sized area. This created the 

whispering gallery, which is like a circular wall of 

mirrors to the electron. 

“An electron that hits the step head-on can tunnel 

straight through it,” said CNST researcher Nikolai 

Zhitenev. “But if electrons hit it at an angle, their 

waves can be reflected and travel along the sides 

of the curved walls of the barrier until they began 

to interfere with one another, creating a nanoscale 

electronic whispering gallery mode.” 

The team can control the size and strength, i.e., the 

leakiness, of the electronic whispering gallery by 

varying the STM tip’s voltage. The probe not only 

creates whispering gallery modes, but can detect 

them as well. 

CNST/UMD Postdoctoral Researcher Yue Zhao 

fabricated the high mobility device and performed 

the measurements with her colleagues Fabian 

Natterer and Jon Wyrick. A team of theoretical 

physicists from the Massachusetts Institute of 

Technology developed the theory describing 

whispering gallery modes in graphene. 

Graphene-based quantum electronic resonators 

and lenses have as yet untold potential, but if 

conventional optics is any guide, the ramifications 

could be huge. 

Creating and probing electron whispering-gallery modes in graphene, Y. Zhao, J. Wyrick, F. D. Natterer, J. F. Rodriguez-Nieva, C. Lewandowski, K. Watanabe, T. Taniguchi, L. S. Levitov, N. B. Zhitenev, and 

J. A. Stroscio, Science 348, 672–675 (2015). 

4 
GOOD VIBRATIONS: MEASURING PHONONS IN GRAPHENE
 

CNST scientists, leading a worldwide group 

of researchers, have developed a method for 

measuring crystal vibrations in graphene. 

Understanding these vibrations is a critical step 

toward controlling future technologies based on 

graphene, a one-atom thick form of carbon. 

Carbon atoms in graphene sheets are arranged in 

a regularly repeating honeycomb-like lattice—a 

two-dimensional crystal. Like other crystals, when 

enough heat or other energy is applied, the forces 

that bond the atoms together cause the atoms 

to vibrate and spread the energy throughout the 

material, akin to how the vibration of a violin’s 

string resonates throughout the body of the violin 

when played. 

And just like every violin has its own unique 

character, each material vibrates at unique 

frequencies. The collective vibrations, which have 

frequencies in the terahertz-range (a billion billion 

oscillations per second), are called phonons. 

Understanding how phonons interact gives clues 

as to how to put in, take out or move energy 

around inside a material. In particular, finding 

effective ways to remove heat energy is vital to the 

continued miniaturization of electronics. 

One way to measure these tiny vibrations is to 

bounce electrons off the material and measure 

how much energy the electrons have transferred to 

the vibrating atoms. But it’s difficult. The technique, 

called inelastic electron tunneling spectroscopy, 

elicits only a small blip that can be hard to pick out 

over more raucous disturbances. 

“Researchers are frequently faced with finding 

ways to measure smaller and smaller signals,” 

says CNST/SNSF Postdoctoral Researcher Fabian 

Natterer, “To suppress the chaos and get a grip 

on the small signals, we use the very distinct 

properties of the signal itself.” 

Unlike a violin that sounds at the lightest 

touch, according to Natterer, phonons have a 

characteristic threshold energy. That means they 

won’t vibrate unless they get just the right amount 

of energy, such as that supplied by the electrons in 

a scanning tunneling microscope (STM). 

To filter the phonons’ signal from other distractions, 

the researchers used their STM to systematically 

alter the number of electrons moving through 

their graphene device. As the number of electrons 

were varied, the unwanted signals also varied in 

energy, but the phonons remained fixed at their 

characteristic frequency. Averaging the signals 

over the different electron concentrations diluted 

the annoying disturbances, but reinforced the 

phonon signals. 

The team was able to map all the graphene 

phonons this way, and their findings agreed 

well with their Georgia Tech collaborators’ 

theoretical predictions. 

According to NIST Fellow Joe Stroscio, learning 

to pick out the phonons’ signal enabled them to 

observe a peculiar and surprising behavior. 

“The phonon signal intensity fell off sharply when 

we switched the graphene charge carrier from 

holes to electrons—positive to negative charges,” 

says Stroscio. “A clue to what’s initially enhancing 

the phonons’ signals and then causing them 

to fall off are whispering gallery modes, which 

become filled with electrons and stop the phonons 

from vibrating when we switch from hole to 

electron doping.” 

The team notes that this effect is similar 

to resonance-induced effects seen in small 

molecules. They speculate that if the same effect 

were happening here, it could mean that the 

system—graphene and STM—is mimicking a 

giant molecule, but say that they still don’t have 

a firm theoretical foundation for what’s happening. 

The high purity graphene device was fabricated 

by CNST/UMD Postdoctoral Researcher in the 

CNST NanoFab. 

Tunneling electrons from a scanning tunneling microscope tip excite phonons in a graphene lattice. Blue arrows indicate the 

direction of moving carbon atoms for one of the low-energy phonon modes. 

Credit: Wyrick/NIST 

Strong asymmetric charge carrier dependence in inelastic electron tunneling spectroscopy of graphene phonons, F. D. Natterer, Y. Zhao, J. Wyrick, Y.-H. Chan, W.-Y. Ruan, M.-Y. Chou, K. Watanabe, T. Taniguchi, 

N. B. Zhitenev, and J. A. Stroscio, Physical Review Letters 114, 245502 (2015). 

5 
OXIDATION ON ALUMINUM ANODES DEGRADES PERFORMANCE OF SOLID
 

STATE BATTERIES
 

Researchers working at the CNST, the University 

of Maryland, and Sandia National Laboratories, 

have for the first time imaged the inner workings 

of experimental solid-state batteries as they 

charged and discharged while making detailed 

measurements of their electrochemical health. 

Their work has helped explain why the batteries 

rapidly lose performance and suggests a way for 

improving them. 

While most batteries on the market today have 

liquid electrolytes, solid-state batteries have, 

as the name implies, a solid one. Not needing a 

liquid makes these batteries amenable to high 

throughput manufacturing techniques and opens 

the door to making them smaller, safer, thinner, and 

even flexible. In fact, the entire battery assembly 

can be little more than a few micrometers thick. 

In commercially available lithium-ion batteries 

used in cell phones, for example, the anode (the 

side of the battery where electrons flow out to 

a circuit) is usually made of carbon. But in these 

new solid-state batteries, scientists have been 

experimenting with other materials, including 

aluminum because it’s so light, an important 

consideration for mobile devices. These batteries’ 

performance degrades rapidly after a small number 

of charge and discharge cycles. In fact, they lose 90 

percent of their capacity after 10 cycles. What no 

one knew was why. 

According to University of Maryland researcher 

Marina Leite, most of the work on imaging large 

areas of solid-state batteries has only shown 

snapshots of the device before and after charging 

it. “In effect, they are post mortems of a battery in 

which you try to infer what happened as the battery 

was charging or discharging,” says Leite. “In our 

case, we could follow as the morphology changed 

on the anode’s surface and track how it impacted 

the performance of the battery, quantifying the 

capacity loss while charging and discharging the 

battery and mimicking what happens when a 

battery is in use.” 

Top: A cross-section scanning electron microscope image of a representative Al anode all-solid-state thin-film battery before 

cycling. Bottom: Top down scanning electron microscope images showing the how the aluminum anode surface evolves 

during the first cycling step. By increasing the charging current, the density of clusters also increases (red shows the effect of 

10 nanoamps after 50 minutes, green is 20 nanoamps at 17 minutes, and blue is 30 nanoamps at 3 minutes), indicating that the 

aluminum–lithium alloy formation is a kinetically driven process. 

The imaging technique can be used with any solid 

state battery. It combines a number of different 

tools including photoelectron spectroscopy, 

scanning electron microscopy and Auger electron 

microscopy (which analyzes electrons emitted 

by excited atoms to determine the elemental 

composition of a surface) under high vacuum. The 

setup enables the team to precisely control the 

lithium reaction rate, the battery state-of-charge 

and state-of-discharge, record the electrochemical 

potential, and to correlate these parameters with 

specific changes in the electrode’s structure and 

chemical composition. 

Their experiments revealed that the batteries’ 

performance degrades due to oxidation of the 

surface of the aluminum anode. The aluminum 

oxide, which appear as cottage cheese-like 

lumps, captures lithium ions and prevents them 

from returning to the cathode during recharging. 

Fewer lithium ions in the cathode means 

the returning electrons have fewer places to 

return to, progressively reducing the batteries’ 

energy capacity. 

“The formation of an alloy at the surface of 

the anode strongly suggests that in order to 

successfully use aluminum as an electrode its 

surface needs to be protected by adding a different 

material that will not alloy,” says CNST Project 

Leader Andrei Kolmakov. 

Leite further notes that new research will focus 

on the anode’s surface-driven reactions and the 

critical role they play in the ultimate performance of 

these types of batteries, instead of the electrolyte/ 

anode interface as is common with other 

battery architectures. 

Insights into capacity loss mechanisms of all-solid-state Li-ion batteries with Al anodes, M. S. Leite, D. Ruzmetov, Z. Li, L. A. Bendersky, N. C. Bartelt, A. Kolmakov, and A. A. Talin, Journal of Materials Chemistry A 2, 

20552–20559 (2014). 

6 
7 

MIND THE GAP: NANOSCALE SPEED BUMP COULD REGULATE PLASMONS 

FOR HIGH-SPEED DATA FLOW 

The name sounds like something Marvin 

the Martian might have built, but the 

“nanomechanical plasmonic phase modulator” is 

not a doomsday device. Developed by a team of 

government and university researchers, including 

scientists from the CNST, the innovation harnesses 

tiny electron waves called plasmons. It’s a step 

towards enabling computers to process information 

hundreds of times faster than today’s machines. 

Computers currently shuttle information around 

using electricity traveling down nanoscale 

metal wires. Although inexpensive and easy to 

miniaturize, metal wires are limited in terms 

of speed due to the resistance in the metal 

itself. Fiber optics use light to move information 

about 10,000 times faster, but these and other 

nonmetallic waveguides are constrained by pesky 

physical laws that require critical dimensions to be 

at least half the wavelength of the light in size; still 

small, but many times larger than the dimensions 

of current commercial nanoscale electronics. 

Plasmonics combines the small size and 

manufacturability of electronics with the high 

speeds of optics. When light waves interact with 

electrons on a metal’s surface, strong fields with 

dimensions far smaller than the wavelength of the 

original light can be created—plasmons. Unlike 

light, these plasmons are free to travel down 

nanoscale wires or gaps in metals. 

The team, which included researchers from Rutgers, 

the University of Colorado at Colorado Springs, 

and Argonne National Laboratory, fabricated 

their device using commercial nanofabrication 

equipment at the CNST NanoFab. Small enough to 

serve in existing and future computer architectures, 

this technology may also enable electrically tunable 

and switchable thin optical components. 

The plasmonic phase modulator is effectively 

an inverted, nanoscale speed bump. Eleven gold 

strands are stretched side by side like footbridges 

across a 23-micrometer gap just 270 nanometers 

above the gold surface below them. Incoming 

plasmons, created by laser light at one end of 

the array, travel though this air gap between the 

bridges and the bottom gold layer. 

The plasmonic phase modulator is an inverted, nanoscale speed bump. Gold strands are stretched side by side across a gap 

just 270 nanometers above the gold surface below them. Incoming plasmons travel though this air gap between the bridges and 

the bottom gold layer. Lowering the “bump” with a control voltage that squeezes the gap and makes the device function like a 

plasmon phase modulator. 

When a control voltage is applied, electrostatic 

attraction bends the gold strands downwards into 

a U shape. At a maximum voltage—close to the 

voltages used in today’s computer chips—the gap 

narrows, slowing the plasmons. As the plasmons 

slow, their wavelength becomes shorter, allowing 

more than an extra half of a plasmonic wave to 

fit under the bridge. Because it’s exactly out of 

phase with the original wave, this additional half 

wavelength can be used to selectively cancel the 

wave, making the bridge an optical switch. 

At 23 micrometers, the prototype is relatively large, 

but according to CNST researcher Vladimir Aksyuk, 

their calculations show that the device could be 

shortened by a factor of 10, scaling the device’s 

footprint down by a factor of 100. According to 

these calculations, the modulation range can be 

maintained without increase in the optical loss, as 

the length and the size of the gap are reduced. 

“With these prototypes, we showed that 

nanomechanical phase tuning is efficient,” says 

Aksyuk. “This effect can be generalized to other 

tunable plasmonic devices that need to be made 

smaller. And as they get smaller, you can put more 

of them on the same chip, bringing them closer to 

practical realization.” 

Compact nanomechanical plasmonic phase modulators, B. S. Dennis, M. I. Haftel, D. A. Czaplewski, D. Lopez, G. Blumberg, and V. A. Aksyuk, Nature Photonics 9, 267–273 (2015). 
 

 

 

 

 

 

 

NEW ATOMIC LAYER DEPOSITION TECHNIQUE COATS HIGH-ASPECT-RATIO 

NANOPOROUS MEMBRANES WITH PLATINUM 

Engineers in the CNST NanoFab have used 

atomic layer deposition (ALD) to make a 

conformal coating of platinum inside a highaspect-ratio (60 μm high with a 0.2 μm diameter) 

nanoporous anodic alumina membrane (AAO). 

High-surface membranes of this type have been 

in great demand for applications ranging from 

catalysis to fuel cells to biosensors. 

By demonstrating that ALD can be used to 

coat platinum, the researchers’ results provide 

a pathway to introducing self-assembled 

monolayers of thiol molecules which can adhere 

to the platinum. A range of proteins can then 

be immobilized by the thiol layer. The high 

aspect ratio increases the exposed surface 

area, resulting in functionalized membranes 

with protein concentrationsapproximately two 

orders of magnitude greater than on a planar 

substrate. This increased surface area opens up 

the possibility of numerous novel applications 

in biosensing. 

With more typical physical and chemical vapor 

deposition techniques, thin films are deposited 

on top of the substrate, where they typically cover 

the tops of nanopores rather than coating inside 

them. ALD forms a thin film on the surface by a 

self-limiting chemical reaction at the interface 

between the coating material and the substrate, 

allowing the material to infiltrate inside the 

structures instead of aggregating on the top. ALD 

has been demonstrated as an effective technique 

for the conformal coating of metal oxides inside 

high aspect ratio AAO structures, but until now 

only limited penetration depth has been achieved 

inside high-aspect nanostructures when ALD is 

used with metals. 

The engineers tuned the process deposition 

temperature and precursor exposure time in 

order to enhance both the infiltration depth and 

the conformal coating of the platinum inside the 

AAO membranes. They then used cross-sectional 

scanning electron microscopy, energy dispersive 

x-ray spectroscopy, and small angle neutron 

Top view scanning electron micrograph of a nanoporous 

anodic alumina membrane. 

scattering to analyze the platinum coverage and 

layer thickness inside the AAO nanopores. 

According to the engineers, their conformal coating 

technique is potentially very useful for making highaspect-ratio surfaces and other structures with 

high surface to volume ratios for use in conjunction 

with functional materials with a broad range of 

biological and catalytic applications. 

Enhancing the platinum atomic layer deposition infiltration depth inside anodic alumina nanoporous membrane, A. Vaish, S. Krueger, M. Dimitriou, C. Majkrzak, D. J. Vanderah, L. Chen, and K. Gawrisch, 

Journal of Vacuum Science & Technology A 33, 01A148 (2015). 

MAGNETO-OPTICAL TECHNIQUE MEASURES FIELDS FROM INDIVIDUAL
 

MAGNETIC NANOPARTICLES
 

I

n two recent studies, CNST scientists showed 

that the thin layers of magnetic cobalt they 

had developed to study the fundamental physics 

of magnetic noise, also function as extremely 

sensitive magnetic sensors. The researchers 

demonstrated these new sensors by measuring 

the magnetic properties of nickel particles only a 

few billionths of a meter wide. 

Using thin cobalt layers as sensors has significant 

advantages over other sensing methods. The 

material has an intrinsic amplification property, 

which transforms the extremely small magnetic 

signature of a nanoparticle into a much larger 

optical signal for easy and rapid measurement. The 

optical nature of the method furthermore allows 

measurement of many particle simultaneously 

under a microscope objective, yielding a 

multiplicative speedup over other techniques. 

The researchers believe their work is an example of 

how fundamental research in measurement science 

often has applications in practical technologies. 

The tiny magnetic particles they studied are widely 

used for nanoscale diagnostics, therapeutics, 

and robotics but, until now, could not be rapidly 

characterized on an individual particle basis. The 

sensing layers can function without cryogens or 

vacuum, making the technique accessible to the 

hundreds of laboratories around the world involved 

in magnetic research. 

According to CNST/UMD Postdoctoral Researcher 

Andy Balk, scientists will be able to use this 

technique to finely tune the magnetic properties 

of small magnetic particles and devices, which 

could lead to advances in medical therapeutics, 

diagnostics, and nanorobotics. 

Top: A thin cobalt layer (gray) detects the magnetic 

state of the nickel nanoparticle sample (yellow). Tiny 

magnetic fields from the nanoparticle sample (small 

red and blue shapes) are amplified (white arrows) by 

an electromagnet (red coil underneath the cobalt layer) 

into much larger signals (large red and blue ovals). The 

scientists monitored how these amplified signals changed 

in response to magnetic field from a set of electromagnets 

mounted on either side of the cobalt layer (red coils, 

right and left). A microscope objective for measurement 

is shown schematically above the cobalt layer. 

Bottom: Experimental data showing amplification of the 

otherwise invisible signal from the sample nanorod. 

Critical behavior of zero-field magnetic fluctuations in perpendicularly magnetized thin films, A. L. Balk, M.D. Stiles, and J. Unguris, Physical Review B 90, 184404 (2014).
 

Magnetometry of single ferromagnetic nanoparticles using magneto-optical indicator films with spatial amplification, A. L. Balk, C. Hangarter, S. M. Stavis, and J. Unguris, Applied Physics Letters 106, 112402 (2015).
 

8 
 

VLADIMIR AKSYUK ELECTED FELLOW OF THE AMERICAN
 

PHYSICAL SOCIETY
 

CNST researcher Vladimir Aksyuk has been 

elected a Fellow of the American Physical 

Society (APS). His fellowship citation notes his 

“contributions to the development of integrated 

photonic and mechanical microsystems, for 

pioneering work in using such systems to enable 

both telecommunications and novel nanoscale, 

high-throughput, measurement methods, and for 

contributions to the understanding of the Casimir 

force.” Fellows comprise no more than one half of 

one percent of the APS membership. This status 

is awarded to recognize outstanding contributions 

to physics. His name and fellowship citation were 

published in the March 2015 issue of APS News. 

Aksyuk is a Project Leader in the Nanofabrication 

Research Group. He received a B.S. in Physics 

from Moscow Institute of Physics and Technology 

and a Ph.D. in Physics from Rutgers University. 

Following research as a Member of Technical 

LEARNING CLEANROOM 

SKILLS THROUGH 

HANDS-ON EXPERIENCE 

Paul Barrett, an Undergraduate Researcher in the 

NanoFab Operations Group, adjusting the Denton 

Discovery 550 sputtering system. Paul recently 

completed a 12-week internship working in the 

CNST NanoFab as part of a program with the 

Northeast Advanced Technological Education 

Center. The internship at the CNST provides 

an opportunity to gain hands-on training and 

experience working in a nanotechnology facility. 

The experience gained from this internship helps 

qualify students to compete for highly skilled 

jobs working as an engineering technician in 

semiconductor manufacturing. These jobs can 

pay as much as $50,000 to $60,000 per year. At the 

CNST, Paul supported the NanoFab staff, assisting 

in regular equipment repair and maintenance. 

Staff and then Technical Manager at Bell Labs, 

he joined the research staff at NIST. Vladimir’s 

research focuses on the design and fabrication 

of novel optical microelectromechanical systems 

(MEMS). He holds more than 30 patents, and has 

published over 40 papers. In 2000 he received the 

Bell Labs President’s Gold Award, in 2005 was 

named among MIT Technology Review magazine’s 

TR35, and in 2008 received a Distinguished 

Alumni award for Early Career Accomplishments 

from Rutgers Graduate School. He is currently 

developing multiple schemes to use optical MEMS 

and nanoelectromechanical systems (NEMS) to 

address problems in nanomanufacturing. 

He was presented with his fellowship certificate at 

the meeting of the Forum on Industrial and Applied 

Physics on March 3, 2015 at the APS March 

Meeting in San Antonio, TX. 

Vladimir Aksyuk has been elected a Fellow of the 

American Physical Society . 

9 
 

 

ROBERT CELOTTA, DANIEL PIERCE, AND JOHN UNGURIS SHARE 2015 

KEITHLEY AWARD FOR ADVANCES IN MEASUREMENT SCIENCE 

CNST researchers Robert Celotta, Daniel 

Pierce, and John Unguris were honored with 

the 2015 Joseph F. Keithley Award for Advances 

in Measurement Science. The three researchers 

were cited for “the invention and development 

of electron spin sources and detectors, and their 

application to measurement science.” 

The Keithley Award recognizes physicists who 

have been instrumental in the development of 

measurement techniques or equipment that have 

impact on the physics community by providing 

better measurements. It is made annually to one 

or a few individuals working in the same area and 

is endowed by Keithley Instruments, Inc. and the 

Instrument and Measurement Science Topical 

Group. The award was created to honor Joseph 

F. Keithley for his outstanding contributions 

and numerous accomplishments in the area of 

sensitive and precision instrument development 

and measurement techniques. Recipients 

receive a prize of $5,000 and a certificate citing 

their contributions. 

Robert Celotta is the current and founding Director 

of NIST’s Center for Nanoscale Science and 

Technology. During his career at NIST, he was a 

long-time Leader of the Electron Physics Group. 

His primary research activities have included 

nanomagnetics, magnetic imaging, the use of 

scanning tunneling microscopy for nanostructure 

characterization and assembly, the optical control 

of free atoms, and the generation, detection, 

and application of free electron polarization 

to measurement. 

Daniel T. Pierce is a NIST Fellow Emeritus. As a 

Postdoctoral Researcher at ETH-Zurich working 

on early spin-polarized photoemission studies, 

Dan and his collaborators, H.C. Siegmann and F. 

Meier, discovered spin-polarized photoemission 

from gallium arsenide. This discovery formed the 

basis for the spin polarized electron gun developed 

by Pierce and coworkers when he joined the 

NIST in 1975. The polarized electron gun was 

applied to studies of surface magnetism and 

Robert Celotta, Daniel Pierce, and John Unguris were honored with the 2015 Joseph F. Keithley Award for Advances in 

Measurement Science. 

aided the invention (with Celotta and Unguris) of 

a low-energy, fist-sized spin-polarization analyzer 

ideal for scanning electron microscopy with 

polarization analysis, a high-resolution magnetic 

imaging technique. 

CNST Electron Physics Group Project Leader 

John Unguris joined NIST as a National Research 

Council postdoctoral research associate 

investigating the application of electron spin 

measurements to various surface-sensitive 

spectroscopies. This work led to the development 

(in collaboration with Pierce and Celotta) of an 

electron microscopy technique for directly imaging 

magnetic nanostructures, scanning electron 

microscopy with polarization analysis (SEMPA). He 

has since used SEMPA to measure the magnetic 

properties of a wide variety of structures, including 

ultrathin patterned magnetic films, oscillatory 

exchange-coupled magnetic multilayers, and 

multiferroic heterostructures. 

Celotta, Pierce, and Unguris were presented with 

the award on March 2, 2015 during a special 

session at the American Physical Society March 

Meeting in San Antonio, TX. 

10 
 

 

 

RECENT PUBLICATIONS BY CNST STAFF RESEARCHERS
 

Below is a list of recent publications by CNST 

staff researchers. Visit the CNST Publications 

Portal (nist.gov/cnst/pubs/index.cfm) to view full 

text versions of these papers and a complete list of 

publications from research supported by the CNST, 

including work performed in the NanoFab and by 

CNST grant recipients. 

Compact nanomechanical plasmonic phase 

modulators, B. S. Dennis, M. I. Haftel, D. A. 

Czaplewski, D. Lopez, G. Blumberg, and V. A. 

Aksyuk, Nature Photonics 9, 267–273 (2015). 

Electrical conductivity and grain boundary 

composition of Gd-doped and Gd/Pr codoped ceria, W. J. Bowman, J. Zhu, R. Sharma, 

and P. A. Crozier, Solid State Ionics 272, 9–17 

(2015). 

Absorption spectroscopy and imaging from 

the visible through mid-infrared with 20 nm 

resolution, A. M. Katzenmeyer, G. Holland, K. 

Kjoller, and A. Centrone, Analytical Chemistry 87, 

3154–3159 (2015). 

Magnetometry of single ferromagnetic 

nanoparticles using magneto-optical 

indicator films with spatial amplification, A. 

L. Balk, C. Hangarter, S. M. Stavis, and J. Unguris, 

Applied Physics Letters 106, 112402 (2015). 

Photodetectors: high-gain and low-drivingvoltage photodetectors based on organolead 

triiodide perovskites (Adv. Mater. 11/2015), R. 

Dong, Y. Fang, J. Chae, J. Dai, Z. Xiao, Q. Dong, 

Y. Yuan, A. Centrone, X. C. Zeng, and J. Huang, 

Advanced Materials 27, 1967 (2015). 

Vibrational and optical spectroscopies 

integrated with environmental transmission 

electron microscopy, M. Picher, S. Mazzucco, S. 

Blankenship, and R. Sharma, Ultramicroscopy 150, 

10–15 (2015). 

Nonlinear ferromagnetic resonance shift in 

submicron Permalloy ellipses, F. Guo, L. M. 

Belova, and R. D. McMichael, Physical Review B 

91, 064426 (2015). 

Near-field asymmetries in plasmonic 

resonators, V. Aksyuk, B. Lahiri, G. Holland, and 

A. Centrone, Nanoscale 7, 3634–3644 (2015). 

In situ SEM study of lithium intercalation 

in individual V2

O5 nanowires, E. Strelcov, 

J. Cothren, D. Leonard, A. Y. Borisevich, and A. 

Kolmakov, Nanoscale 7, 3022–3027 (2015). 

New insights into subsurface imaging of 

carbon nanotubes in polymer composites via 

scanning electron microscopy, M. Zhao, B. 

Ming, J.-W. Kim, L. J. Gibbons, X. Gu, T. Nguyen, 

C. Park, P. T. Lillehei, J. S. Villarrubia, A. E. Vladár, 

and J. A. Liddle, Nanotechnology 26, 085703 

(2015). 

Probing electric field control of magnetism 

using ferromagnetic resonance, Z. Zhou, M. 

Trassin, Y. Gao, Y. Gao, D. Qiu, K. Ashraf, T. Nan, 

X. Yang, S. R. Bowden, D. T. Pierce, M. D. Stiles, 

J. Unguris, M. Liu, B. M. Howe, G. J. Brown, S. 

Salahuddin, R. Ramesh, and N. X. Sun, Nature 

Communications 6, (2015). 

Magnetic structure and anisotropy of [Co/ 

Pd]5

/NiFe multilayers, L. Tryputen, F. Guo, F. Liu, 

T. N. A. Nguyen, M. S. Mohseni, S. Chung, Y. Fang, 

J. Åkerman, R. D. McMichael, and C. A. Ross, 

Physical Review B 91, 014407 (2015). 

Spin Hall effect and irreversible 

thermodynamics: center-to-edge transverse 

current-induced voltage, W. M. Saslow, 

Physical Review B 91, 014401 (2015). 

Enhancing the platinum atomic layer 

deposition infiltration depth inside anodic 

alumina nanoporous membrane, A. Vaish, S. 

Krueger, M. Dimitriou, C. Majkrzak, D. J. Vanderah, 

L. Chen, and K. Gawrisch, Journal of Vacuum 

Science & Technology A 33, 01A148 (2015). 

New ion source for high precision FIB 

nanomachining and circuit edit, A. V. Steele, B. 

Knuffman, and J. J. McClelland, in Proceedings of 

the 40th International Symposium for Testing and 

Failure Analysis, (Houston, TX, 2014), p. 293–297. 

11 
 

CENTER FOR NANOSCALE 

SCIENCE AND TECHNOLOGY 

The CNST is a national user facility purposely designed to accelerate 

innovation in nanotechnology-based commerce. Its mission is to operate a 

national, shared resource for nanoscale fabrication and measurement and 

develop innovative nanoscale measurement and fabrication capabilities to 

support researchers from industry, academia, NIST, and other government 

agencies in advancing nanoscale technology from discovery to production. 

The Center, located in the Advanced Measurement Laboratory Complex 

on NIST’s Gaithersburg, MD campus, disseminates new nanoscale 

measurement methods by incorporating them into facility operations, 

collaborating and partnering with others, and providing international 

leadership in nanotechnology. 

If you would like to subscribe to this newsletter, go to 

http://www.nist.gov/cnst/newsletters.cfm, enter your e-mail address, 

and follow the on-screen instructions. Alternately, you may request 

a subscription via email or phone. 

SUPPORTING THE 

DEVELOPMENT OF 

NANOTECHNOLOGY 

FROM DISCOVERY TO 

PRODUCTION 

Center for Nanoscale Science and Technology 

National Institute of Standards and Technology 

100 Bureau Drive, MS 6200 

Gaithersburg, MD 20899-6200 

Phone: 301-975-8001 

E-mail: cnst@nist.gov 

CNST TO HOST WORKSHOP ON ADVANCING 

NANOPARTICLE MANUFACTURING 

On October 7th and 8th, the CNST will host a 

two-day workshop, Advancing Nanoparticle 

Manufacturing, in Building 215, Room C103 - 106. 

Following decades of research and development, 

commercial products enabled by nanoparticles 

are poised to have broad impact in diverse sectors 

of the global economy, ranging from electronics 

to healthcare to energy. However, applications 

of nanoparticles remain limited by challenges 

at all stages of the manufacturing process, from 

production and purification, to characterization and 

integration of nanoparticles into products. 

The workshop will gather experts from across 

industry, government, and academia to discuss 

these technical challenges, as well as application 

forecasts and market insights, determining the 

path forward in nanoparticle manufacturing. In 

particular, Advancing Nanoparticle Manufacturing 

will focus on the manufacturing of nanoscale Initiative. To learn more, including information 

particles, rods, and tubes in the liquid phase. about speakers, registration, and accommodations, 

please visit http://www.nist.gov/cnst/anm.cfm. 

This NIST Workshop is being held under the 

auspices of the NIST Nanomanufacturing 

WWW.NIST.GOV/CNST 150725