2005

Inquiry Science and Technology at the Ames Laboratory

Award-winning bond coat 

A photonic first

Inside a fuel-cell membrane

A U.S. Department of Energy laboratory operated by Iowa State University
Contents table of 2 Beating the Heat

An award-winning bond coat for thermal barrier coatings promises to help gas 

turbine engines “beat the heat” of severe, high-temperature environments.

6 Courting Complex Hydrides

Funds from the Hydrogen Fuel Initiative will enable Ames Lab researchers to 

study new complex hydrides that may help solve the hydrogen-storage puzzle.

8 What Makes a Fuel-Cell Membrane Tick?

Nuclear magnetic resonance is giving researchers a clearer picture of the 

molecular structure of the membrane used in hydrogen fuel cells. 

10-11 INtouch 

Visitors, awards and conferences – Ames Lab is a busy place.

12 Oxygen Monitoring Made Simple

Basic research has led to development of an oxygen sensor with a uniquely 

simple design and the creation of a new sensor company.

14 “Tall” Crystals from Tiny Templates

Researchers are making multilevel, four-millimeter-square photonic crystals in 

the open air to reduce fabrication costs.

17 INtouch 

Ames Laboratory hosts future scientists.

18 Searching for the “Holy Grail”

Ames Lab researchers are looking at a series of praseodymium compounds as a 

model for studying magnetic behavior for a whole group of rare earth materials.

21 INtouch

Ames Lab celebrates the 2005 World Year of Physics.

22 Balancing the Load

Adaptive algorithms are optimizing efficiency in high-performance 

computing environments. 

24 Photo Gallery

(front cover) With an eye to the future, Brian Gleeson, along with co-principal investigator Dan Sordelet, is developing a 

new bond coat for thermal barrier coatings that will allow engine components, such as the turbine blade he is holding, 

operate more successfully in severe, high-temperature environments. 

(back cover) A “treasure hunt” for interesting photos led to the discovery of these shiny circles found scattered and 

abandoned in a laboratory drawer. The eye-catching hoops are actually the concentric rings and cover for a steam bath. 

2

12

14
Editor

Steve Karsjen

Managing Editor

Saren Johnston

Designer

Jan Weedman 

Photography Interns

Shauna Stephenson

Stephanie Brunia

Copyright 2005 by Ames Laboratory. 

All rights reserved. For additional 

information about Ames Laboratory 

or topics covered in this publication, 

please contact:

Editor, Inquiry

Ames Laboratory

111 TASF

Ames, Iowa 50011-3020

(515) 294-9557

www.ameslab.gov

from the Director

e are pleased to begin this issue of Inquiry with both a thank-you and 

a note of congratulations. Our thanks go to Secretary of Energy Samuel 

Bodman for his visit to the Ames Laboratory in June, only four months after 

assuming the duties of Secretary. The Secretary was extremely impressed with 

the several scientific presentations by Ames Laboratory researchers. He also 

expressed his high regard for the national labs in maintaining the nation’s 

leadership in science and technology.

Our congratulations go to Brian Gleeson, director of Ames Lab’s Materials 

and Engineering Physics Program, and Dan Sordelet, senior scientist, for 

winning a 2005 R&D 100 Award. Brian and Dan have developed novel 

platinum-modified nickel-aluminide bond coats for thermal barrier coatings. 

The new bond coats promise to greatly improve the durability of gas turbine 

engines, allowing them to operate at higher temperatures. Their awardwinning work leads the stories in this year’s Inquiry.

Ames Laboratory scientists continued to carry out innovative basic and 

applied research in a variety of scientific areas during the past year. Outstanding 

work led by Kai-Ming Ho and Kristen Constant brought together the disciplines of condensed matter physics and materials engineering 

to significantly advance research on photonic bandgap crystals. Their unique modification of a technique known as “microtransfer 

molding” may considerably reduce the costs of fabricating photonic crystals.

An example of basic research is being carried out by Bill McCallum and a team of researchers from across the Lab. The group is 

studying a series of praseodymium-nickel-silicon compounds to determine the relationship between molecular structure and important 

magnetic properties, such as magnetorestriction. The hope is that these compounds can serve as a theoretical model for understanding 

other rare earth-nickel-silicon alloys and for enhancing their potential uses.

In the Laboratory’s Scalable Computing Lab, Masha Sosonkina is developing adaptive algorithms to execute high-performance 

applications efficiently in dynamically changing computing environments. In particular, she has been working on a co-scheduler for 

GAMESS, a computational chemistry code, to make the simultaneous execution of GAMESS calculations more efficient.

Getting into the “fuel of the future” game, Vitalij Pecharsky and a team of Ames Lab researchers will be investigating complex 

hydrides in an effort to help solve the problem of hydrogen fuel storage – how to carry enough hydrogen onboard a vehicle to travel 

even moderate distances between refueling stops. The work is the focus of $1.6 million in funding awarded to Ames Laboratory from 

the DOE’s $64 million Hydrogen Fuel Initiative.

As you read about these intriguing research efforts in the 2005 Inquiry, I’m sure you’ll agree that Ames Laboratory scientists are 

engaged in some very exciting activities in their efforts to find solutions to our nation’s energy problems.

W

Secretary Bodman (left) and Tom Barton

Inquiry is published annually by the Ames Laboratory Office of Public Affairs. Iowa State University operates the Laboratory for the U.S. Department of Energy under contract W-7405-Eng-82. Located on the ISU 

campus, the Ames Laboratory is a member of the university’s Institute for Physical Research and Technology, 

a network of scientific research centers
Inquiry

2005

2

Beating the Heat

A new bond coat may mean longer life 

for gas turbine engines

Dan Sordelet and Brian Gleeson’s new bond coat for thermal barrier coating systems will allow higher operating 

efficiencies for gas turbine blades in aircraft engines.

by Saren Johnston
3 Inquiry

2005

 lying from coast to coast or country to 

country has become a matter of routine 

for many people in today’s fast-paced, 

workaday world. And frequent flyers have 

learned to take advantage of their valuable 

in-air time while jetting through the skies 

at 300-400 miles per hour. Some strategize 

delicate business maneuvers or scrutinize 

stock portfolios, while others mentally 

rehearse invited talks or happily succumb 

to the intrigue of a Dan Brown novel. 

All this and more airline passengers can 

accomplish at 30,000 feet, compliments of 

the hardworking gas turbine engines that 

keep their carriers of choice up there in the 

“friendly skies.”

Not surprisingly, then, along with all 

the dependency on air travel that today’s 

“commuter” has developed, there has come 

a steady demand for better, more efficient 

gas turbine engines that can operate at 

elevated temperatures. Addressing that 

need, Ames Laboratory and Iowa State 

University researchers have developed a new 

bond coat for thermal barrier coatings, or 

TBCs, that may allow gas turbine engines 

in aircraft and other power-generating 

technologies to better withstand severe, 

high-temperature environments. The basic 

research effort could provide a TBC system 

with significantly improved reliability and 

durability of turbine blades, thus enabling 

higher operating efficiencies and extending 

engine lifetimes.

Just what is a TBC?

Commercial thermal barrier coatings 

consist of three layers. The first layer is 

typically an aluminum-rich bond coat 

that is based on the compound nickelaluminum, or NiAl. The bond coat is 

applied directly to the turbine blade. The 

second layer is a thin, thermally grown 

oxide, or TGO, which forms as the 

aluminum in the bond coat oxidizes. The 

third layer, a thin (around half a millimeter) 

ceramic top coat, has a low thermal 

conductivity and, therefore, acts as a barrier 

against heat damage.

“By applying a thermal barrier 

coating to a turbine blade, it is possible 

to increase the combustion temperature 

of the engine, which leads to significantly 

improved efficiency in gas turbines,” says 

Dan Sordelet, an Ames Laboratory senior 

scientist. He explains that the ability of the 

bond coat to oxidize and form a continuous, 

slow-growing and adherent TGO layer is 

critical to creating a resilient and reliable 

thermal barrier coating.

Things can and do go wrong

Sordelet emphasizes that cracking or 

breaking apart of the TGO layer due to 

time and service in a severe environment 

is one of the main causes of failure in a 

TBC system and the associated engine 

components. Also, at temperatures around 

1100 degrees Celsius (2012 degrees 

Fahrenheit) and above, the aluminum in the 

bond coat begins to diffuse more rapidly 

into the substrate, changing the overall 

bond coat composition.

 “If enough aluminum diffuses into 

the substrate, eventually a phase change, 

which is a change in the crystal structure, 

occurs and can lead to large-scale distortion 

of the bond coat surface and subsequent 

failure of the TBC system,” says Sordelet. 

Elaborating, he adds, “Initially, there is 

a very thin TGO layer sitting on a very 

flat bond coat surface. If the bond coat 

continues to lose aluminum so that phase 

transformations take place, conditions 

will change from thin and flat to thin 

and ‘rumpled.’ Stresses develop, and the 

likelihood for the top coat to come off 

increases rapidly.”

A unique bond coat composition developed by Dan Sordelet (left) and Brian 

Gleeson may one day become the standard in thermal barrier coatings that 

protect gas turbine blades, like the ones they’re holding, from heat damage.

F
4 Inquiry 2005

This electron microscope image of the new Ames 

Lab/ISU bond coat composition after an identical 

number of thermal cycles shows essentially the 

same surface topography as the starting surface 

(i.e., no rumpling).

Understanding the alloy – the 

platinum bonus

Working to improve the reliability of 

TBC systems, Sordelet and Brian Gleeson, 

director of Ames Laboratory’s Materials 

and Engineering Physics Program and an 

ISU professor of materials science and 

engineering, have performed experiments 

on various nickel-aluminum-platinum, 

or Ni-Al-Pt, alloy samples made by Ames 

Laboratory’s world-renowned Materials 

Preparation Center.

“Dan and I received funding 

from the Offi ce of Naval Research to 

conduct fundamental research on the 

Ni-Al-Pt system, including experimental 

determination of isothermal phase 

diagrams,” says Gleeson. “The phase 

diagrams provided much-needed guidance 

for elucidating the relationships between 

phase constitution/composition and 

properties in this system.”

Quite unexpectedly, the two researchers 

found that platinum additions signifi cantly 

improved the oxidation resistance of nickelrich bulk alloys having the same type of 

structure as the turbine alloy. Without 

platinum, these alloys form a relatively fastgrowing TGO scale that is prone to spall, 

or break up, during thermal cycling. By 

adding platinum, the alloys become highly 

resistant to oxidation, forming a tenacious, 

slow-growing TGO scale. But Sordelet and 

Gleeson weren’t satisfi ed yet.

A little dab will do

“In the typical design of alloys for 

oxidation resistance, you always fi nd that 

adding a little sprinkle of this and a little 

sprinkle of that can have dramatic effects,” 

says Sordelet. “Well, Brian’s intuition to 

sprinkle either zirconium or hafnium was 

remarkably accurate.” As the researchers 

This electron microscope image of a commercial bond 

coat after thermal cycling shows how the thermally 

grown oxide becomes “rumpled,” leading to subsequent 

spallation of the ceramic top coat and failure of the entire 

TBC system.
added a little bit of either or both to the 

nickel-rich compositions, things improved 

tremendously.

“With the addition of hafnium, 

oxidation rates went down by up to an 

order of magnitude,” Sordelet says. “We 

now have growth rates that are the lowest 

ever reported. It’s quite remarkable!”

In current aluminum-rich bond coat 

alloys, only a very small amount (e.g., 

<0.1 wt.%) of zirconium or hafnium 

may be added to improve oxidation 

before adding too much is detrimental, 

causing catastrophic oxidation failure. 

In commercial coating production, it is 

extremely diffi cult to achieve an adequately 

uniform distribution of such a small 

amount of metals like these in a costeffective way.

“Fortunately, in the new nickel-rich 

bond coat, we have observed signifi cant 

reductions in oxidation rates over a 

wide concentration, from 0.5 to 4 wt.% 

hafnium,” Gleeson emphasizes. “These 

are no longer ‘trace’ levels to a processing 

engineer and can thus be easily alloyed 

homogeneously throughout the material.” 

This attribute gives Sordelet and Gleeson’s 

new coating a huge processing window, 

which they both say has been very desirable 

to people they’ve visited within the coatings 

industry.

Bulk luck

Their work with the bulk alloys 

led Gleeson and Sordelet to yet another 

fortunate result. They discovered that 

platinum changed the diffusion behavior 

of aluminum in their nickel-rich 

compositions. 

“Instead of aluminum going from 

the bond coat down into the substrate, 

5 Inquiry 2005

it was moving up from the substrate into 

the bond coat,” explains Gleeson. “This 

phenomenon is referred to as ‘uphill 

diffusion,’ and it’s a consequence of the 

strong chemical interaction between 

aluminum and platinum. With our new 

bond coating compositions, the substrate 

can act as a large reservoir for aluminum 

and hence maintain the protective growth of 

the oxide layer.”

The two researchers have recently 

demonstrated that their new coatings can 

offer signifi cant benefi ts over current stateof-the-art bond coatings used in advanced 

TBC systems. “We have been working with 

an aeroengine manufacturer, and the results 

to date have been extremely encouraging,” 

says Sordelet.

For more information:

Brian Gleeson, (515) 294-4446

gleeson@ameslab.gov

Dan Sordelet, (515) 294-4713

sordelet@ameslab.gov

Research funded by:

Offi ce of Naval Research

Brian Gleeson and Dan Sordelet have won a 2005 R&D 100 

Award for the development of novel platinum-modifi ed nickelaluminide coatings that deliver unprecedented oxidation 

resistance and phase stability as bond coat layers in thermal 

barrier coatings. The new bond coats promise to signifi cantly 

improve the reliability and durability of gas turbine engines, 

allowing them to operate at higher temperatures and extending 

their lifetimes. The R&D Magazine program, now in its 42nd

year, honors the top 100 products of technological signifi cance 

marketed or licensed during the previous calendar year. The 

winning of an R&D 100 Award provides a mark of excellence 

known to industry, government and academia as proof that 

the product is one of the most innovative ideas of the year. 

Since 1984, Ames Laboratory has earned 15 prestigious R&D 

100 Awards.
6 Inquiry 2005

ydrogen is being touted as the fuel of 

the future, a clean-burning, renewable and 

inexpensive replacement for petroleum. 

But a major stumbling block for 

hydrogen-powered vehicles is figuring out 

a way to carry enough hydrogen onboard 

to travel even moderate distances between 

refueling stops.

A group of Ames Laboratory 

researchers will be investigating a possible 

solution to that problem thanks to $1.6 

million in funding announced recently 

by Department of Energy Secretary 

Samuel Bodman as part of a $64 Million 

Hydrogen Fuel Initiative. Funding for the 

project will be spread over three years.

“With compressed hydrogen gas, you 

simply can’t carry a tank big enough to 

travel very far,” Ames Lab senior scientist 

Vitalij Pecharsky says. “The answer is a 

hydrogen-rich, solid fuel that mimicks 

the hydrogen content of methane, where 

four hydrogen atoms encapsulate a single 

carbon atom.”

Unlocking the hydrogen

So why not just use methane? 

According to Pecharsky, methane and 

similar hydrocarbon compounds have 

covalent bonds that keep the hydrogen 

atoms tightly “locked” in place. The 

energy required to break those bonds is 

very high compared to the energy you’d 

get from the hydrogen produced. Also, 

methane and other hydrocarbons that 

come from oil are not renewable. The 

ideal solution would be a hydrogen-rich 

solid material that gives up its hydrogen 

atoms easily, through moderate heating 

or by other means. These materials could 

also be “recharged” – absorbing “new” 

hydrogen atoms during refueling from a 

pressurized hydrogen gas source. 

That’s why Pecharsky and fellow Ames 

Lab scientists Marek Pruski, Victor Lin 

and Scott Chumbley are looking at some 

novel materials – light-metal alanates, 

borohydrides, amides, imides, and their 

derivatives – that have a total hydrogen 

content exceeding 10 percent by weight. 

Shaking things up

A key component in the research 

project is solvent-free mechanochemical 

processing, a technique Ames Laboratory 

researchers had shown back in 2002 to 

Courting Complex Hydrides

Lab gets $1.6 million to study complex hydrides

by Kerry Gibson

Marek Pruski, left, and Vitalij Pecharsky stand in front of a new nuclear magnetic 

resonance magnet that Pruski will use to study complex hydride materials. 

Joining Pruski and Pecharsky on the $1.6 million Hydrogen Fuel Initiative project 

will be Victor Lin and Scott Chumbly.

H
work well when applied to complex 

hydrides. The process uses variable energy 

milling to modify both the structure and 

properties of hydrides, and potentially, 

to make them easily rechargeable with 

hydrogen. Materials to be processed are 

placed in a hardened steel vial along with 

steel balls. The vial is vigorously shaken 

and mechanical energy transferred into the 

system alters the crystallinity of the solids 

and provides mass transfer, eventually 

breaking down the solids and releasing 

hydrogen, or combining the materials and 

hydrogen gas into new compounds.

“Processing these materials without 

the use of solvents is important,” 

Pecharsky says, “because once a material 

is dissolved, its structure fundamentally 

changes. Creating these complex hydride 

compounds in solid state will allow us 

to look at the molecular structure to see 

if there are ways to more easily get the 

hydrogen back out of these systems.”

Keeping it “small”

Another ingredient the group will 

use is called nanostructuring. Ames Lab 

chemist Victor Lin has developed a way 

of using the nanoscale pores in a selfassembling polymer as “molds” to precisely 

control the size of the material particles 

going into the milling process. Smaller 

particles have higher surface energies, and 

surface energy may be a decisive factor 

in shifting thermodynamic equilibrium. 

Lowering the size of particles to a few 

nanometers also reduces the distances over 

which the mass transport takes place, thus 

improving the kinetics – the rates of the 

reactions – of complex hydride-hydrogen 

systems.

Synthesizing various combinations 

and sizes of materials will provide samples 

to be studied and characterized using 

a variety of high-tech methods. Ames 

Lab metallurgist Scott Chumbley hopes 

that scanning and transmission electron 

microscopy will give researchers a closeup look at the structure of the processed 

materials. The team will also rely on the 

expertise of Ames Lab senior scientist 

Marek Pruski in using solid-state nuclear 

magnetic resonance. Earlier studies 

performed by Pruski’s group proved that 

NMR is uniquely suited for the studies 

of complex phases resulting from the 

milling process. Coupled with X-ray 

powder diffraction and other traditional 

materials characterization techniques, 

researchers hope to gain a fundamental 

understanding of the relationships between 

the chemical composition, bonding, 

structure, microstructure, properties and 

performance of these materials.

“We’ll look at the rates of absorption 

and desorption of hydrogen as well as 

the cycling properties of these materials 

at various temperatures and pressures,” 

Pecharsky says. “Furthermore, we plan to 

modify these nanoparticles with titanium 

and other transition metal catalysts and 

perform a full array of characterization and 

hydrogenation-dehydrogenation property 

tests on these metal-doped nanostructured 

hydrides.” 

Predicting outcomes

Parallel with the materials’ 

characterization, the group will work with 

physicist Purusottam Jena of Virginia 

Commonwealth University to develop 

first-principle theoretical models based 

on the experimental data. Those models 

will then be used to predict outcomes of 

further experiments. The predictions and 

actual results will be compared to see if the 

theory holds or needs further modification. 

Ultimately, the theoretical model will be 

used to help steer research toward the most 

promising compounds. 

For more information:

Vitalij Pecharsky, (515) 294-8220

vitkp@ameslab.gov

Research funded by:

Hydrogen Fuel Initiative

A mechanical ball mill, similar to the one shown above, is used to create organic 

compounds without the use of solvents. The materials to be combined are placed 

in the canister along with the steel balls. Operating similar to a paint shaker, mill 

shakes the canister and the mechanical energy going into the system is transferred 

to the materials, eventually combining them at the molecular level.

7 Inquiry 2005
8 Inquiry

ne of the keys to hydrogen fuelcell technology is a thin, plastic film 

that “magically” separates water into its 

component parts of hydrogen and oxygen 

and at the same time releases electrons 

that generate power from the fuel cell. 

The membrane, known commercially as 

Nafion® (see photo, page 9), looks like a 

clear, heavy vinyl, but because of what it’s 

able to do, the material is more than worth 

it’s weight in gold.

Developed by DuPont, Nafion® has 

been around for roughly 30 years and is 

the commercial standard for the proton 

exchange membrane in fuel cells. Despite 

that history and commercial success, 

surprisingly little is known about its 

molecular structure or just how it works.

“It takes 24 of these to make a 

hydrogen fuel cell used in buses,” says Ames 

Laboratory chemist Klaus Schmidt-Rohr, 

as he held a roughly one-foot-square sheet 

of Nafion®, “so it costs several thousand 

dollars just for the membrane material. 

In order to develop more affordable 

alternatives, we need to understand the 

molecular structure of Nafion® and how it 

works.”

NMR probes stucture

Schmidt-Rohr has been studying the 

membrane material for about five years, 

primarily using a technique called nuclear 

magnetic resonance, or NMR. The 

spectroscopic technique basically involves 

placing the material within a magnetic field 

and measuring how energy levels of the 

atomic nuclei split as the material transitions 

from one energy state to another. In general, 

the more complex the structure of the 

What Makes a 

Fuel-Cell Membrane Tick?

Qiang Chen prepares to load a sample holder 

contain a piece of Nafion® membrane into the NMR 

probe. NMR allows researchers a detailed view of 

a material’s structure in its solid state when the 

material is non-crystalline in nature and dissolving it 

would alter the structure.

Using NMR to probe Nafion®’s structure by Kerry Gibson

O

2005
9 Inquiry

material, the sharper or more distinctive its 

NMR signature will be.

“A material like polystyrene has a 

broad NMR signature because its structure 

is amorphous,” Schmidt-Rohr says. 

“Perfluoronated polymers such as Teflon® 

or Nafion® register these sharp peaks, 

indicating a surprising amount of order 

– in other words, a crystalline structure.”

According to Schmidt-Rohr, electron 

scattering techniques can provide an 

overall view of the structure, while NMR 

allows “us to go segment-by-segment and 

look at the structure from the bottom up.”

Bent backbones

Previous studies of Teflon® show it 

has rod-like, helical structures that spin 

rapidly, about a million times a second. 

This “backbone” is hydrophobic – water 

hating – which helps explain its nonstick 

nature, and the rods pack neatly into 

parallel bundles.

In his study of Nafion®, SchmidtRohr saw a similar backbone pattern 

with some important differences. The 

signature line of the backbone showed up 

nicely, but it had “defects” along the chain 

approximately every 14 units.

“We thought now that we have these 

straight (backbone) elements, they’ll want 

to crystallize and pack nicely together,” he 

says. “We did one more experiment and 

looked at how one local piece is parallel 

to another. What we found really threw 

us off because they weren’t parallel. They 

weren’t random, but they weren’t nicely 

packed either.”

The literature on the structure 

Nafion® proposed about a dozen different 

models, but none of them were consistent 

with the observations of Schmidt-Rohr’s 

NMR studies. 

“We discovered these ionic sulfunate 

side groups with hair-like ends,” he says. 

“These structures are charged and are 

hydrophilic – they like water – while the 

backbone is hydrophobic.”

New model

Schmidt-Rohr developed what he 

calls an “alternating curvature model” that 

shows the backbones aligning along the 

bends and the hairlike structures clustering 

together. The material is crystalline in 

areas where the backbones align, roughly 

10 percent of the overall structure. And 

in order for a polymer chain to have the 

required stiffness, the theory is that the 

density of the hairs matches the density of 

the backbone.

Moreover, the clusters of hydrophilic 

hairs form pores 3-5 nanometers in size 

that hold water. The next step is to figure 

out how the water moves from one pore to 

the next.

“Nafion® has an extremely high 

permeability for water,” Schmidt-Rohr 

says, “almost like water moving through 

water. One important feature that is 

missing is a channel or means for the water 

to move between the pores. To figure 

that out, we’ll have to do low-temperature 

studies to slow the transfer of water.”

Unlocking the structural secrets of 

Nafion® may help not only in development 

of materials for fuel-cell membranes but 

other purposes as well.

“The material has these 3-5 nanometer 

pores,” Schmidt-Rohr says, “so if we were 

able to fill those with other counter-ions, it 

could provide optical properties for a variety 

of nanoscale applications.”

For more information:

Klaus Schmidt-Rohr, (515) 294-6105

srohr@iastate.edu

Research funded by:

DOE Office of Basic Energy Sciences

 Materials Chemistry Division

Klaus Schmidt-Rohr, right, and 

graduate student Qiang Chen stand 

in front of the nuclear magnetic 

resonance chamber. Tiny samples 

of Nafion® membrane are placed in 

a probe, which Chen is holding, and 

lowered into the high magnetic field 

within the chamber.

Based on his findings, SchmidtRohr has developed an “alternating 

curvature” model of Nafion® in which 

the backbone aligns between bends, 

and the hairlike structures cluster 

together to form 3-5 nanometer pores. 

The hairlike structures are hydrophilic, 

so water tends to collect in the pores.

2005
10 Inquiry 2005

INtouch

Secretary Bodman 

Visits Ames Lab

t is very difficult for me to imagine 

anyone anywhere who is better qualified to 

serve our nation as Secretary of Energy than 

Samuel Bodman,” said Ames Laboratory 

Director Tom Barton as he introduced the 

Secretary at the all-hands meeting, Friday, 

June 3. “Leading our nation to a secure 

energy future is about as daunting a task as 

I can imagine, frankly, but we are, indeed, 

fortunate that someone with such incredibly 

impressive and appropriate credentials as has 

Secretary Bodman is on the job.”

Coming to the podium, the Secretary 

thanked members of the audience for turning 

out in such great numbers. “I want you 

to know that I’m particularly pleased to be 

here,” he said, noting that he was born and 

raised in the neighboring state of Illinois.

Secretary Bodman explained that he’s 

an engineer and brings that perspective to 

his job with the Department of Energy. 

“The national laboratories, like this one, 

have a special meaning to me,” he said. 

“The laboratories have been enormously 

productive organizations in helping to 

maintain our nation’s leadership in science 

and technology. This lab is one of the 

smaller labs in the group, but that does not 

reflect on the preeminence of the work that is 

done here. The work of materials technology 

I was prepared to believe before I got here is 

quite extraordinary, and that was reinforced 

once I arrived.”

The Secretary expressed his admiration 

for how well the Lab works on an 

interdisciplinary basis. “You seem to have 

perfected that art,” he said, praising the 

Lab’s unique ability to integrate students, 

both graduate and undergraduate, into its 

research endeavors. Commenting on the 

fact that student employees account for 

some 20 percent of the Lab’s workforce and 

that thousands of them have received their 

degrees while working here, the Secretary 

said, “That’s really extraordinary. It’s quite 

amazing and something to be treasured 

– something for you to focus on.” 

Secretary Bodman encouraged the 

Lab to continue its interest in working on 

technologies and products that could have 

commercial possibilities. He emphasized 

that the partnerships that include 

government funding in support of science 

research, the potential commercial partners 

in these endeavors, research universities, 

and venture capitalists have, in his opinion, 

helped create what we call today the 

American economy. “Without that process, 

we wouldn’t have the economy we have 

today,” he said. “It has been something 

that the Ames Laboratory seems to have a 

real focus on in its own way, and I would 

continue to encourage you to realize and 

treasure what you have here because it really 

is something quite special.”

Concluding his remarks, Secretary 

Bodman said, “I’m very pleased and 

honored to have this job. This is the first 

time that a person has taken on the job 

as Secretary of Energy who is burdened 

by some knowledge of energy,” he added, 

Flanked by security personnel and Ames Lab officials, Secretary 

Bodman (right) begins his Ames Laboratory tour accompanied by 

Director Tom Barton (center) and Alan Goldman, division director 

of Science and Technology.

drawing appreciative laughter from the 

audience. “Hopefully you’ll look at me as 

someone who has some understanding of 

what to do and how to do it. I’ve got this 

job, and I’ll be very serious about it,” he 

promised, adding, “I’ll count on your help 

as we go forward.” 

 

Senior metallurgist Karl Gschneidner 

visits with Secretary Bodman about 

magnetic refrigeration during the 

Secretary’s tour of Ames Laboratory.

“I
INtouch

11 Inquiry 2005

ohn Corbett, Ames Laboratory senior 

chemist, was named the recipient of the 

2005 Spedding Award, the top honor for 

researchers in the field of rare-earth science 

and named for the first director of Ames 

Laboratory.

Corbett, who is also a distinguished 

professor of chemistry in the College of 

Liberal Arts and Sciences at Iowa State 

University, is the 11th recipient of the 

Spedding Award, which is given annually 

by the Rare Earth Research Conference. 

The award is given in recognition of 

excellence and achievement in research 

centered on the science and technology of 

rare earths and consists of a medal mounted 

on a plaque and a prize of 

$1,000, sponsored by Bracco 

Research USA Inc.

The award was presented 

to Corbett at the 24th Rare Earth Research 

Conference in June in Keystone, Colo. 

During the conference, Corbett presented 

an awards lecture on his many years of work 

with reduced rare-earth metal compounds. 

Corbett is the third Ames Laboratory 

researcher to receive the Spedding Award. 

Senior physicist Sam Legvold was a cowinner of the third award, and senior 

metallurgist Karl A. Gschneidner was the 

sixth winner.

 The Spedding Award is named in 

honor of Frank Spedding, a longtime Iowa 

State chemistry professor and one of the 

nation’s leading atomic scientists. Spedding 

was a pioneer researcher with rare earths 

and organized 

and directed the 

chemistry phase 

at Iowa State 

of the historic 

Manhattan Project. 

He founded the Institute for Atomic 

Research and the Ames Laboratory of 

what was then the U.S. Atomic Energy 

Commission.

A member of the National Academy 

of Sciences, Corbett has been an Ames 

Laboratory researcher and a faculty 

member in ISU’s chemistry department 

since 1952. During that time, he has 

served as a division chief and program 

director at the Ames Laboratory and as 

chair of the ISU chemistry department.

 Corbett Wins 

Spedding Award

J

 ore than 200 of the world’s leading researchers in the field of quasicrystals gathered 

in Ames, May 22-26, for the Ninth International Conference on Quasicrystals. Selection 

of Ames as the host city among the likes of Beijing, Avignon, Tokyo, Stuttgart, Bangalore, 

and Zurich is testimony to the strength of materials research being conducted at Ames 

Laboratory and Iowa State University. This year was also only the second time the U.S. has 

hosted the event since the first conference was held in 1986.

Quasicrystals, the focal point of the conference, are typically aluminum-rich metallic 

alloys that are somehow able to form into crystals – usually with a five-fold symmetry – in 

which the atoms are ordered, but without the periodicity common in crystalline materials. 

Quasicrystalline materials are hard, slippery, poor conductors of heat, and resistant to 

attack by other chemicals. This makes them particularly useful for applications requiring 

resistance to wear, low adhesion or a thermal barrier, such as machinery operating in abrasive 

environments, coatings inside pipelines or cookware, or electrical insulators.

A highlight of the conference was the awarding of the inaugural Jean-Marie Dubois 

Award, named for one of the key researchers in the field. Dubois, Director of Research at 

the Centre National de la Recherche Scientifique in Paris, presented during the conference 

and was recently named as the 2007 winner of The Minerals, Metals & Materials Society’s 

(TMS’s) prestigious Robert Franklin Mehl Award.

The Dubois Award was presented to Professor An-Pang Tsai of Sendai University for his 

“fundamentally important discoveries of new quasicrystalline phases.” The award consists of 

a $2,000 cash prize and a plaque.

Quasicrystal World Focuses on Ames

Jean Marie Dubois, left, stands with 

An-Pang Tsai who received the firstever Dubois Award for excellence in 

quasicrystal research.

M 
 n the world of sensor technology, oxygen 

sensors represent a very large, multifaceted 

and ever-expanding market. The medical 

industry, alone, accounts for a whopping 

portion of that market, considering oxygen 

monitoring is essential to the daily health 

care regimens of millions of individuals 

throughout the world. Other fields where 

oxygen sensors have applications include 

environmental, biological, food packaging, 

health and safety, and aerospace.

Now, basic research on the photophysics 

of luminescent organic thin films and organic 

light-emitting devices, or OLEDs, by Ames 

Laboratory senior physicist Joseph Shinar, 

together with sensor research by Ruth 

Shinar, a chemist at Iowa State University’s 

Microelectronics Research Center, has led to 

Integrated Sensor Technologies, Inc. ISTI is 

an emerging company focused on creating 

12 Inquiry 2005

Oxygen Monitoring 

 

integrated oxygen/OLED sensors. The novel 

sensors will greatly reduce the expense and 

size, lessen the energy consumption and ease 

the process of sensor fabrication, explains 

Ruth Shinar, CEO of ISTI. 

She notes that ISTI’s sensor 

development is in the “exploratory stage,” 

which has been allowed to progress thanks 

to the assistance in securing research funding 

provided by ISU’s Institute for Physical 

Joseph Shinar (center), Ruth Shinar and Zhaoqun Zhou are developing a new integrated sensor technology 

that is expected to result in low-cost sensor (micro)arrays for multianalyte detection.

Sound collaboration 

 

Made Simple

results in a new sensor company

I

by Saren Johnston
Research and Technology. She says IPRT 

technology commercialization specialists 

were instrumental in helping ISTI obtain 

a Small Business Innovative Research grant 

from the National Institutes of Health. 

Sensibly and stylishly simple

Joseph Shinar says the proposed oxygen 

sensor will be palm-sized or smaller and that 

the beauty of the device lies in the fact that 

the sensor will be structurally integrated 

with its ultrathin light source, an OLED, in 

a uniquely simple design. 

Unlike conventional oxygen sensors 

that are expensive and sometimes bulky, 

ISTI’s integrated sensors provide a uniquely 

simple integration approach that could 

result in very compact devices. Perhaps 

best of all, the new sensor will be far less 

expensive, costing approximately $200, due 

to its essentially disposable modular OLED/

sensing element components. 

ISTI’s novel integrated sensor design 

may ultimately allow the use of miniaturized 

sensor arrays with the capability of “front” 

and “back” luminescence detection, 

providing a more versatile device with the 

capability of detecting multiple analytes 

by utilizing different color, individually 

addressable, OLED pixels with matching 

sensing elements. 

Out of the lab and into the box

Bhaskar Choudhury, an electrical 

engineering graduate student working 

with Microelectronics Research Center 

Director Vikram Dalal, and Zhaoqun Zhou, 

a physics graduate student, fabricate the 

OLEDs for the new oxygen sensors. The 

Ames Lab Electronics Shop is designing and 

fabricating a prototype electronics module, 

power supply and photodetector assemblies 

– a challenging task.

 “It’s one thing to demonstrate an 

oxygen sensor using these OLEDs in the 

lab, but to assemble a working device, you 

have to design and build the electronics and 

put everything in a box and calibrate the 

whole thing,” says Joseph Shinar. “It’s a lot 

of work, not to mention that it needs to 

compete successfully with existing devices.”

Ruth Shinar says the experience of 

transferring the knowledge gained in the 

research lab to an actual product has been 

quite an adventure. She acknowledges IPRT 

for its strong support in getting Integrated 

13 Inquiry 2005

This brilliant blue organic lightemitting device, or OLED, is integral to 

a new oxygen sensor that is making 

its way from basic research at Ames 

Laboratory to marketable product for 

the new Ames company, Integrated 

Sensor Technologies, Inc. The novel 

sensor technology structurally 

integrates a photoluminescence-based 

oxygen sensing element with its OLED 

light source. 

Joseph Shinar has seen his original 

research on the photophyhsics of 

luminescent organic thin films and 

organic light-emitting devices go from 

bench science to a novel integrated 

oxygen sensor and a new sensor 

company.

Sensor Technologies, Inc. off to a good start, 

and Mike Upah, program manager at ISU’s 

Pappajohn Center for Entrepreneurship, 

for his support. “All involved are strongly 

focused on the mission of technology 

transfer,” she says.

For more information:

Joseph Shinar, (515) 294-8706

shinar@ameslab.gov

Ruth Shinar, (515) 294-5895

rshinar@iastate.edu 

Original research funded by:

DOE Office of Basic Energy Sciences,

 Materials Science and Engineering 

 Division
14 Inquiry 2005

ard to hold and hard to handle, like a 

child in its “terrible twos,” light does what 

it pleases, defying attempts to control its 

behavior. But while the impulsive actions 

of toddlers will probably always challenge 

and test us, scientists are getting better at 

controlling the spontaneous emission of 

light.

The ability to trap and manipulate 

light has been improving steadily since the 

early 1990s when photonic bandgap crystals 

and the possibilities they foretold first began 

to “wow” the scientific community.

Photonic crystals are man-made 

devices that can be constructed to permit 

or block the transmission of light of 

certain frequencies in all directions. This 

characteristic makes them especially 

promising for applications within the field 

of optical communications, where the push 

is on to create a photonic crystal within a 

single computer chip.

The research path to that goal is an 

unbelievably expensive one. But Kai-Ming 

Ho, an Ames Laboratory senior physicist, 

and Kristen Constant, an Iowa State 

University associate professor of materials 

science and engineering, and their coworkers are easing the way by fabricating 

3-D photonic crystal microstructures in 

the open air, something that has never been 

done before.

Nothing like it

Achieving a first in the world of novel 

optical materials, the researchers are making 

photonic crystals four millimeters square 

(approximately one-eighth of an inch 

square) and 12 layers high without benefit 

“Tall” Crystals from Tiny Templates 

Researchers have modified an old technique 

to make 3-D multilayered structures

Jae-Hwang Lee (standing) and Chang-Hawn Kim have developed an innovative 

method based on diffracted moiré fringes for aligning the layers in a photonic 

crystal.

H

by Saren Johnston
15 Inquiry 2005

of a “clean room” environment or the 

multimillion dollar equipment traditionally 

required to create such structures, although 

multi-domains exist in each crystal and 

alignment remains a challenge. The 

fundamental research holds potential for 

significantly reducing the costs associated 

with fabricating photonic crystals.

The project is based on Ho’s original 

1990 work in which he theoretically 

demonstrated the existence of the first 

photonic crystal through his diamond lattice 

structure design. 

That unique design is key to the 

multilayered photonic crystals that members 

of Ho’s and Constant’s research groups are 

making. They have adapted a technique 

called microtransfer molding to create 

templates for fabricating the photonic 

crystals.

“The microtransfer mold technique is 

not new,” says Ho, who is also an Iowa State 

University distinguished professor of physics 

and astronomy. “Modifying it to create 

multilevel lattice structures at micron- and 

submicron-length scales – that is the new 

advance.”

“Slick” work at a small scale

The modified technique involves 

meticulous work at the micron-scale level. 

(For size reference, the period at the end 

of this sentence equals approximately 615 

microns.) First, an elastomer mold is 

created with more than 1,000 microchannels 

on its surface. The channels are filled with 

a liquid polymer filler using a manually 

operated tool. The filler is then solidified 

by ultraviolet light. Next, the solidified 

polymer rods in the channels are coated 

with a second polymer that acts as a glue, 

bonding the filler to a glass substrate. Once 

hardened, the elastomer mold is peeled off, 

leaving a set of parallel polymer rods on 

the substrate – one layer of the polymer 

template. By repeating the procedure, 

in principle, any number of multilayered 

structures is achievable. To convert the 

template to a ceramic photonic crystal, the 

template is over-infiltrated with a titania 

slurry. The structure is fired to 550 degrees 

Celsius (1022 F) to remove the template 

and sinter the titania structure. For metallic 

photonic crystals, free-standing templates 

are used with gold sputter deposition.

Stacking microstructures

Ho and Constant credit many of 

the fabrication advances to the unique 

skills of the young scientists they mentor: 

postdoctoral fellow Chang-Hwan Kim; 

current graduate students Jae-Hwang Lee, 

Yong-Sung Kim, and Ping Kuang; and 

former graduate student Henry Kang, 

now at Hewlett Packard in Oregon. 

They are conquering what is perhaps 

the biggest challenge – aligning the 

multiple layers that make up the 

photonic crystals. 

The 1,000 plus rods per layer 

in a four-millimeter-square photonic 

crystal are only 2.5 microns apart. 

“The placement of each rod is so 

precise,” says Constant. “It’s hard to 

imagine that we can put something 

down within a micron or half a 

micron.”

Ho adds, “If you make a mistake 

in one layer, it will disrupt the next 

one and spoil the rest of the sample. 

In order to build multilayers, you 

This green laser diffraction pattern of a 4-layer metallic photonic crystal (inset) 

shows the alignment of a 4-layer PBG crystal that was created by Kai-Ming Ho and 

Kristen Constant‘s research team.
16 Inquiry 2005

need to get things right successively.” 

Lee knows the kind of concentration 

that requires. He has constructed a 12-

layer template for a photonic crystal and 

modestly admits, “I can stack more than 

this; however it will task my patience!”

To improve the alignment, Lee and 

Chang-Hwan Kim came up with an 

ingenious method based on diffracted moiré 

fringes that has proven indispensable. Ho 

explains, “Photonic crystals are periodic 

structures, so any shifts in periodicity will 

show up over a much larger area. Those 

shifts are called fringes,” he says. “Let’s say 

that the space between rods in a layer is 

off by one hundredth of the 2.5 microns 

that separates them. That means that with 

every 100 rods, there will be a change. The 

fringes that appear will not be 2.5 microns 

in size, but 100 times that. The better the 

alignment, the farther apart those fringes are 

spaced, so the fringe pattern tells you how 

good the alignment is.”

Constant praises the project’s blended 

research team of physicists and materials 

engineers. “We’ve established an expertise 

with microtransfer molding. It’s a niche 

we can fill that other people aren’t doing. 

When they hear that we’re doing this in 

open air, it really amazes them. It amazes 

me, too,” she admits, “especially when you 

realize that a speck of dust can disrupt the 

whole structure.”

Ho notes that the care and expertise of 

the project’s team members is overcoming 

the open-air obstacles. “It’s a high-quality, 

low-cost process – that’s the key – and it’s 

achieved by a lot of engineering ingenuity,” 

he says.

The colorful designs in these two 

images represent moiré fringes. The 

top image is conventional moiré 

fringes, while the bottom image is 

diffracted moiré fringes. The enhanced 

contrast provided by the diffracted 

moiré fringes is essential to the process 

of aligning the layers in a photonic 

crystal. 

This image of a 12-layer microstructure 

shows the capability of the modified 

microtransfer mold technique for 

fabricating multilayer photonic crystals.

The ability of Ho and Constant’s 

research team to fabricate working 

photonic crystals outside of a clean 

room is impressive considering that 

just a speck of dust can result in defects 

like the one shown above.

For more information:

Kai-Ming Ho, (515) 294-1960

kmh@ameslab.gov

Kristen Constant, (515) 294-3337

constant@iastate.edu

Research funded by:

DOE Office of Basic Energy Sciences

 Materials Science and Engineering 

 Division
INtouch

17 Inquiry

 t’s difficult to say who anticipates Ames Laboratory’s High School and Middle 

School Science Bowls more – the volunteers or the student participants. It 

probably doesn’t matter because year after year both the “question-asking” and the 

“question-answering” teams always seem to have a ball! 

The High School Science Bowl saw the hometown team from Ames High 

School take top honors in the 2005 competition, earning the right to represent the 

Iowa Region in the Department of Energy’s National Science Bowl in Washington, 

D.C.

After the High School Science Bowl, it was full speed ahead with plans for 

the Middle School event that included an academic competition and a hydrogen 

fuel-cell car challenge. Berg Middle School of Newton was victorious in the 

car challenge, while Central Academy of Des Moines captured first place in the 

academic competition to receive an all-expenses-paid trip to the National Middle 

School Science Bowl in Golden, Colo.

 n eight short weeks this summer, 10 

undergraduate students from colleges and 

universities across the country experienced 

life in a real-world research setting at the 

Ames Lab. The students were at the Lab as 

part of the Department of Energy’s Science 

Undergraduate Laboratory Internship, or 

SULI, program. 

The student internships focused on 

the research the students performed in 

laboratories under their mentors’ guidance. 

The SULI program culminated with a 

student research poster session, which was 

enthusiastically attended by scientists, staff 

and students. 

The following comments are just two 

of the many positive thoughts expressed 

by both students and mentors about their 

experiences in the SULI program. 

Iver Anderson, mentor and senior 

metallurgist – “My experience with the 

SULI program is colored (brightly) by 

the extremely high quality of the student, 

Shamus Cronin, that I worked with this 

summer. Shamus was willing and able to 

jump into the 

project that we 

designed and was 

always friendly 

and positive. I 

only hope that he 

got half as much 

enjoyment out of 

his experience as 

my other group 

members and I 

received during 

his stay at Ames 

Lab. His experimental results were of high 

(publishable) value, and his careful analysis 

will help us to develop at least one new 

manuscript. My only complaint is that 

the program was too short. Sign me up 

again!”

Amanda DeVries, SULI student 

participant – “The SULI program opened 

my eyes to diversity in the chemistry field 

as well as basic organic chemistry lab 

techniques that aren’t always taught in the 

From Student to Scientist

classroom. I worked alongside researchers, 

something I don’t have the opportunity to do 

at the small school I attend. I am thankful 

for the brilliant interns, students, and staff 

I met this summer, and I am thankful for 

the opportunity the SULI program gave me 

to further my education in a way I never 

imagined.”

Science Bowl 

 Scores Big

Travis Monk discusses his research 

poster on photonic bandgap materials 

during the SULI student poster session.

Students from Berg Middle School in Newton, Iowa, do a victory dance after 

winning the Hydrogen Fuel-cell Car Challenge.

I

I

 2005
18 Inquiry 2005

Searching for 

the “Holy Grail”

by Kerry Gibson
19 Inquiry 2005

 n the world of basic research, scientists 

often look for a material or system that 

behaves systematically in order to model its 

behavior. That way, as various factors are 

changed experimentally, the reactions can be 

observed and measured. Theorists can use 

that data to develop complex calculations to 

explain the behavior. 

With a theory in hand, the theorists 

can further change the variables, perform 

new calculations and predict the outcomes, 

while the experimentalists go back to the lab 

and conduct the same tests under the same 

prescribed conditions. Finally, they compare 

the observed results with the predicted 

outcomes to see if the computational theory 

holds.

“It’s sort of like searching for the 

Holy Grail,” says Ames Laboratory senior 

metallurgist Bill McCallum. “The ultimate 

goal would be to choose a combination 

of elements and simply calculate what 

compounds will form and what properties 

those compounds would have. For now, we 

have to work to find systems that will allow 

us to continue to push our ability to calculate 

and understand outcomes.”

Interdisciplinary approach

McCallum coordinates an 

interdisciplinary host of other researchers 

from the Ames Lab’s Materials and 

Engineering Physics and Condensed Matter 

Physics programs who are studying one 

such system, a series of rare earth-nickelsilicon compounds. The group is specifically 

interested in the magnetic properties 

exhibited by various praseodymium-nickelsilicon 

compounds – Pr(n+2)(n+1) Nin(n-1)+2 Sin(n+1), 

where n = 2, 3, 4 and 5.

“We chose these compounds because 

they contain well-defined magnetic 

structures,” McCallum says, “and when we 

made small adjustments in the chemical 

composition, we expected that the magnetic 

properties would change in very systematic 

ways.”

The researchers decided to start 

with samples of the material for the 

n=3 compound Pr20Ni8Si12 (Pr5Ni2Si3). 

However, problems emerged right away in 

trying to control the composition of the 

samples.

“The materials don’t form exactly on 

stoichiometry,” McCallum says, “so while 

we’re calling it Pr5Ni2Si3 we know that it’s 

actually closer to Pr5Ni1.85Si3.1.” 

Finding the "good stuff"

To get around these problems, 

McCallum relied on physicist Paul 

Canfield’s group to grow single crystals 

using flux growth methods. Crystals are 

grown out of a solvent that reduces the 

melting point of the desired compound.

“Even though the melt was of a 

different composition than the one we 

wanted, the correct phase came out of it,” 

McCallum says. “You grow what you want 

and spin off what you don’t want. It’s kind 

of like taking the juice off a roast and after a 

while the fat congeals, you skim that off and 

you’re left with the good stuff.

“There’s a certain amount of guesswork 

involved so you have to either be lucky 

or learn a lot about the phase diagrams,” 

McCallum continues, “and we did some 

of both. We were lucky with our first try 

and then based on experimental data and 

thermodynamic calculations we were able to 

figure out much more detail about the phase 

diagram.”

Although a phase diagram of the 

praseodymium compound existed, it 

I

(facing page) Ames Lab assistant 

scientist Dongmei Wu holds a 

crystalline sample of a praseodymiumnickel-silicon alloy that is the focus 

of research into how the material’s 

magnetic properties are related to its 

molecular structure.

This depiction of the molecular structure of the alloy shows the arrangement 

of trigonal prisms in three neighboring unit cells in the ab-plane.

Praseodymium compounds may serve as models for theorists

= rare earth metal

= nickel

= silicon
20 Inquiry

2005

was apparent that there were significant 

errors. Impurities in the samples used in 

the original investigations seem to be the 

contributing factor, and Ames Lab assistant 

scientist Sasha Tsokol “put in a tremendous 

amount of work confirming and correcting 

the diagrams,” McCallum says.

Once they had the “good stuff” 

to work with, the researchers began 

taking heat capacity measurements and 

fairly precise thermal expansion and 

magnetorestriction measurements. In 

magnetorestriction, the crystal lattice 

of the material pulls in when subjected 

to magnetic fields. However, the 

praseodymium material exhibited unusual 

behavior at certain levels.

“We plotted magnetic moment as a 

function of the temperature in different 

fields,” McCallum explains. “Normally 

the curves come up in scale, but these 

have a peculiar peak. So if we fix the 

temperature and change the field and 

look at the magnetization, it develops this 

peculiar transition. It’s more pronounced 

in the smaller (n=2) concentrations and less 

pronounced in the larger (n=4) ones, but 

the pattern is the same.”

Experimental correlation

Based on the magnetization data for 

the Pr5Ni2Si3, the average magnetic moment 

– the point at which the material aligns 

magnetically – was 1.98. Independent 

neutron diffraction measurements conducted 

by Anna Llobet-Megias at Los Alamos 

National Laboratory yielded an average 

magnetic moment of 2.01. McCallum 

calls those results an “excellent” correlation. 

Though neutron diffraction results aren’t 

in yet, similar results are expected for the 

n=2 (Pr6Ni2Si3) and n=4 (Pr15Ni7Si10) 

compounds.

Even though the crystal structure 

of the praseodymium materials varies, 

the experimental findings help paint a 

consistent picture of what is taking place. 

And that gives the theorists – Condensed 

Matter Physics Program Director Bruce 

Harmon and physicist Min Huang – clearer 

parameters with which to work.

“If we give them just one structure, 

there may be various ways to adjust the 

calculation to fit those results,” McCallum 

says. “But in this material, the various 

parameters that they can adjust should be 

the same in each of the three structures. So 

now we have a much more stringent test 

because they have to find a set of consistent 

parameters that give the correct results for all 

three structures.”

While some experimental “cleanup” work remains, the focus now is on 

developing the theoretical computations to 

explain what takes place. Those theories will 

then be tested by further experimentation.

“There really isn’t an end result in this,” 

McCallum says. “Hopefully, we can take 

what we learn here and apply it to other 

materials.”

For more information:

Bill McCallum, (515) 294-4736

mccallum@ameslab.gov

Research funded by:

DOE Office of Basic Energy Sciences,

 Materials Science and Engineering 

 Division

Ames Lab postdoctoral fellow Yuri Janssen pours molten alloy from a crucible into 

a centrifuge to separate the desired phase during a flux-growth process.
Inquiry

2005

21

INtouch

Physics Fervor

elping the Department of Energy carry out its mission to 

lead the U.S. observance of the 2005 World Year of Physics, Ames 

Laboratory planned and coordinated monthly outreach events that 

highlighted the seldom-recognized but unquestionably important 

role of physics in our everyday lives. Event programs included 

topics for both children and adults. Many of the programs were 

held at the Ames Public Library in conjunction with the library’s 

summer reading program for young people. Among the Ames Lab 

offerings were “Physics Sunny-side Up,” which highlighted the 

many things solar energy does on earth, and “Big Chills and Hot 

Flashes,” which amazed both children and adults with the effects of 

hot and cold on gases, liquids and solids.

A unique program, “Flights of Fancy,” took place at Iowa State 

University’s beautiful Reiman Gardens in the exhibit hall near the 

indoor butterfly wing. The Ames Lab program featured an ISU 

entomologist and an aerospace engineer who introduced both 

youngsters and adults to the physics of butterfly flight and the wide 

array of aerodynamic mechanisms that are involved in the fluttering 

motion of a butterfly’s wings. Visitors then got to make their own 

colorful, larger-than-life butterflies to take home.

An unplanned but fortunate set of circumstances led to a 

fascinating WYP evening with Professor E. N. Economou of the 

Research Center of Crete and department of physics, University 

of Crete, Greece. Economou was visiting Ames Laboratory senior 

physicist Costas Soukoulis who requested a lecture from his friend 

and colleague for Ames Lab’s WYP celebration. Economou spoke 

to a large crowd at ISU’s Memorial Union on the significance of 

two opposing pressures – compressive and expansive – to our world. 

The balance of those opposing pressures governs the formation 

of greater and greater structures, from unimaginably small quarks 

and leptons to larger living structures that include viruses, cells and 

humans to the ever-greater structures of planets, stars and galaxies, 

and finally the observable universe.

Unexpectedly, the WYP turned out to be the perfect impetus 

for getting employees in the mood for Ames Lab’s group outing 

to an Iowa Cubs baseball game. A noon talk, “The Physics of 

Baseball,” by Eli Rosenberg, chair of the ISU physics and astronomy 

department, included “Seinfeld” clips, cartoons and famous baseball 

quotes as well as the more detailed physics of the game. The 

dynamic presentation drew a full house of baseball and physics 

enthusiasts and succeeded in keeping the less-physics-oriented 

audience members on track.

A late summer WYP event planned for the Ames Public 

Library is the “Totally Toy Workshop.” The workshop will provide 

youngsters with several hands-on opportunities to learn about the 

physics of various toys, such as Slinkys, yo-yos, and whistles. Future 

library events that will help round out the 2005 World Year of 

Physics include programs on the physics of the martial arts and the 

physics of champagne.

During an Ames Laboratory World Year of Physics event at 

the Ames Public Library, youngsters respond to the directions 

“be hot” or “freeze” and use a parachute to demonstrate 

what happens to a helium-filled balloon when dipped in liquid 

nitrogen.

While creating their own butterfly works of art at an Ames Lab 

World Year of Physics event on the physics of butterfly flight, 

youngsters learned that there are as many as six different ways 

butterflies flap and rotate their wings to stay airborne.

H
22 Inquiry

2005

e tend to shy away from the word 

“algorithm.” For many of us, the term 

conjures images of lengthy equations and 

formulas that represent mathematical 

or computational worlds in which we 

are not at home. But the fact is that we 

use algorithms every day. A recipe for 

making cookies is an algorithm, as are the 

instructions for building a model airplane 

or the procedures for knitting an afghan.

An algorithm is a set of steps for 

solving a specific problem. The steps must 

be clear-cut and have an obvious stopping 

point. And although algorithms can be 

expressed in most any language, they seem 

to be associated more easily with computer 

programming languages. 

Elegant algorithms

A well-designed algorithm is simple and 

requires the fewest steps possible to solve the 

problem, resulting in time- and cost-savings. 

But creating ingenious algorithms is one of 

the foremost challenges in programming. 

Adaptive algorithms facilitate resolution of 

that challenge. They typically include the 

ability to modify a running program and 

balance system resource allocations to react 

to changing processing conditions.

Most adaptive algorithms operate 

within the parallel computing environments 

associated with supercomputers or cluster 

computers – high-performance computing 

systems with several processors that can 

work on different parts of a single problem 

simultaneously. In a nutshell, adaptive 

algorithms bring several algorithms together, 

so to speak, for the solution of the same 

problem. They also include the mechanisms 

for choosing the most appropriate algorithm 

from the available options. 

“Today’s problems are very complex. 

They might require many software packages 

– not all designed for parallel architecture,” 

says Masha Sosonkina, a computational 

scientist working in the Ames Laboratory’s 

Scalable Computing Lab. “It’s very hard to 

include everything for the solution of those 

problems in a single software package, so 

you might want to have some help.” That 

help comes in the form of middleware, 

which Sosonkina describes as a kind of 

“middleman” that stands between the 

computer resources and the algorithm, itself. 

“Middleware will look at the computer 

resources and, depending on their current 

availability, suggest some new algorithm 

path to the application,” she says. 

Attach, suggest and optimize

High-performance computing allows 

scientists to solve very computationally 

intensive applications, which, Sosonkina 

notes are sometimes written in older 

programming languages. “People already 

have proven codes that work, so we 

don’t want to completely revamp those 

applications,” she says. “What we’d like 

to have is some lightweight modification 

– some kind of helper in the middleware 

to attach itself to these applications and 

give some suggestions on how to optimize 

their performance for a given computing 

environment.”

Sosonkina has been working on 

adaptive algorithms to do just that for the 

General Atomic and Molecular Electronic 

Structure System, better known as 

GAMESS. The computational chemistry 

code includes a hierarchy of quantum 

chemistry methods that help solve problems 

relating to molecules – what they do and 

why they do it.

With a history that goes back to 1977, 

GAMESS is what is known as a legacy code. 

It existed before many recent computer 

science innovations, so some features of 

GAMESS have been made parallel from 

the beginning, and some features have been 

made parallel after the fact. From the early 

1980s to the present, dedicated efforts 

on the parts of Mark Gordon, Ames Lab 

program director of Applied Mathematics 

and Computational Sciences, and Michael 

Schmidt, an Ames Lab associate scientist, 

along with many students and postdoctoral 

Balancing 

the Load Adaptive algorithms ease problem-solving in 

parallel computing environments

Masha Sosonkina

W

by Saren Johnston
23 Inquiry 2005

fellows, have led to the development of new 

functionalities for GAMESS and continued 

parallelization of the code. 

Depending on the size and complexity 

of the molecule under investigation, 

running GAMESS to compute its 

electronic structure can make high demands 

on certain computer resources at various 

stages of the algorithm, or problem-solving 

process. According to Sosonkina, the main 

memory and disk input/output usage are 

the resources most at risk while GAMESS is 

executing multiple calculations.

What’s needed, Sosonkina explains, 

is some type of middleware with a system 

scheduler that can attach to the application, 

“look” in on the execution of concurrent 

jobs and then alert the application to 

the current conditions of the computing 

environment. This “co-scheduler” then 

may change the path of the application to 

adapt it to the chosen environment with 

the goal of balancing computing resources 

and making the simultaneous execution 

of multiple GAMESS calculations more 

efficient.

Integrate to monitor

Sosonkina has developed a coscheduler for GAMESS in collaboration 

with Nurzhan Ustemirov, an ISU 

graduate student working with her in the 

Scalable Computing Lab, and Gordon 

and Schmidt. Because GAMESS has 

been around for so long and continues to 

undergo development, it would be difficult 

to modify the source code to include a 

self-scheduler. Instead, Sosonkina and 

her co-workers are using a middleware 

tool, Network Information Conveyer and 

Application Notification, or NICAN, 

for integration with specific GAMESS 

algorithms that may have multiple 

implementations for a given computation. 

The most appropriate implementation 

depends on the current state of the 

computing environment.

The co-scheduler created from 

integrating NICAN with a GAMESS 

application separates the process of 

monitoring computer resources from that 

of executing the application. It enhances 

the simultaneous execution of GAMESS 

jobs while also relaying information about 

the available main memory to GAMESS. 

The process is an efficient and timely 

one due to the monitoring modules 

within NICAN that watch over different 

system resources. If a resource reaches a 

predetermined critical range, NICAN calls 

up the associated algorithm to “handle” 

the situation, selecting an appropriate 

path to execute the GAMESS job. If the 

critical range for a specific resource is 

never reached, the adaptive measure is not 

initiated, and the GAMESS application 

continues to execute the original job.

Results of experiments conducted on 

identical as well as different molecules by 

Sosonkina and her co-workers show that 

the throughput for GAMESS calculations 

incorporating adaptive algorithms was 

dramatically higher compared to the 

throughput for nonadaptive calculations.

“For the users and developers of 

high-performance applications, adaptive 

algorithms coupled with a middleware 

alleviate the burden of tweaking their 

programming code depending on changes 

in the computing environment,” says 

Sosonkina. “The goal is to increase 

efficiency so computations will finish in 

reasonable time while maintaining a good 

utilization of computing resources.” To 

achieve that goal, Sosonkina says there 

must be a close collaboration between the 

creators of adaptive algorithms and the 

application users and developers. “It’s very 

difficult to know the inside of any highperformance software,” she adds. “We 

need teamwork – we require that input to 

identify the needs of an application.”

The top graph shows the time to 

calculate the structures of 12 identical 

molecules in the order of different initial 

algorithmic paths (from Best to Worst, 

and Arb meaning an arbitrary initial 

ordering).

The bottom graph represents the 

average time taken to complete 12 

identical and distinct jobs. 

Both graphs represent experimental 

results showing that concurrent 

GAMESS jobs, in which the adaptations 

were invoked by NICAN, better utilized 

the computing resources and, for an 

arbitrary initial algorithm ordering, 

resulted in much better performance 

than the nonadaptive case.

For more information:

Masha Sosonkina, (515) 294-6751

masha@scl.ameslab.gov

Research funded by:

DOE Office of Advanced Scientific 

Computing Research

 Mathematical, Information, and 

 Computational Sciences Program 
One of a Kind: Dark sample vials are required for lightsensitive metal complexes used in Ames Laboratory’s 

unique research on the catalytic activation of oxygen.

Photo Gallery

Oxygen Activation Research

Eyes on the Prize: Kelemu Lemma, an Ames Laboratory 

postdoctoral fellow, uses a microliter syringe to withdraw 

a sample of a chromium complex. The procedure is a 

familiar one in studying the material’s reactivity in oxygen 

activation.

Cool, Clear Water: Water is the solvent in all of the 

catalysis research led by Ames Laboratory senior 

chemist Andreja Bakac.

24 Inquiry 2005
Melt Magic: An arc-cast alloy button is placed on a drop-cast mold (left) and 

melted in an arc melter (right). The resulting alloy melt, among other things, 

may ultimately be used to produce high-purity single crystals that allow 

researchers to study and better understand the properties of the material.

View to a Melt: Peering through the window of the Plasma 

Lab Furnace, Ames Laboratory research technician Arne 

Swanson watches as the plasma torch melts the material in 

the sample chamber.

Materials Preparation 

 Center

A Real Hotshot: The Retech Model 150 Plasma 

Lab Furnace in Ames Laboratory’s Materials 

Preparation Center generates temperatures well 

in excess of 10,000 degrees Celsius. The furnace 

can melt reactive metals and alloys without 

the need for crucibles to contain them, thus 

eliminating possible contamination from crucible 

materials.
Ames Laboratory 

111 Technical and Administrative Services Facility 

Ames, Iowa 50011-3020

(515) 294-9557

http://www.ameslab.gov

2005

Ames Laboratory is a U.S. 

Department of Energy laboratory 

seeking solutions to energyrelated problems through the 

exploration of chemical, engineering, materials and mathematical sciences, and physics. 

Established in the 1940s with 

the successful development of 

the most efficient process to 

produce high-purity uranium 

metal for atomic energy, Ames 

Lab now pursues much broader 

priorities than the materials 

research that has given the 

Lab international credibility. 

Responding to issues of national 

concern, Lab scientists are actively involved in innovative 

research, science education 

programs, the development of 

applied technologies and the 

quick transfer of such technologies to industry. Uniquely 

integrated within a university 

environment, the Lab stimulates 

creative thought and encourages 

scientific discovery, providing solutions to complex problems and 

educating tomorrow’s scientific 

talent.

AMES LABORATORY A U.S. Department of Energy laboratory operated by Iowa State University

Inquiry