Microdiffraction images of polarization switching in a thin-film capacitor. The ability of ferroelectric materials to store information resides in their arrangement of atoms with each structure holding a bit of information.

Aug. 23 , 2004 -- Some of this week's stories:

Research reveals why 'flash' memory fades

While the memory inside electronic devices may often be more reliable than ours, it too can worsen over time.

Now a team of scientists from Argonne and the University of Wisconsin-Madison may understand why. The results were published in the June 6 edition of the journal Nature Materials.

Smart cards, buzzers inside watches and even ultrasound machines all take advantage of ferroelectrics, a family of materials that can retain information, as well as transform electrical pulses into auditory or optical signals, or vice versa.

"The neat thing about these materials is that they have built-in electronic memory that doesn't require any power," explained Paul Evans, a UW-Madison assistant professor of materials science and engineering and a co-author of the recent paper.

But there's a problem preventing many of these materials from being used more widely in other technologies, including computers. As Evans said, "Eventually they quit working."

The ability of ferroelectrics to store information resides in their arrangement of atoms with each structure holding a bit of information. This information changes every time the material receives a pulse of electricity, basically switching the arrangement of atoms.

However, each electric pulse — and corresponding change in structure — gradually diminishes the capability of these materials to store and retrieve information until they either forget the information or quit switching altogether. Said Evans, "It could switch 10,000 or even millions of times and then stop working." Engineers call this problem fatigue.

With little evidence for what happens to the structure of ferroelectrics as the material's memory fatigues, Evans and his colleagues decided to look inside this material as its arrangement of atoms, controlled by electrical pulses, switched inside an operating device.

"We'd like to understand how it switches so we could build something that switches faster and lasts longer before it wears out," said Evans.

To create a detailed picture of how the atoms rearrange themselves inside an operating device during each electrical pulse, the researchers used the Advanced Photon Source — the country's most brilliant source of X-rays for research — to measure changes in the location of atoms. By seeing how atoms changed position, the researchers could determine how well the material switched, or remembered information.

"One advantage to working with X-rays is their ability to penetrate deep into materials, which is why they are so extensively used today in medical imaging," said Eric Isaacs, director of Argonne's Center for Nanoscale Materials and also one of the paper's co-authors. "Using this property of X-rays, [we] were able to peer through layers of metal electrodes in order to study ferroelectric fatigue in a realistic operating device."

He adds that the very high brightness of the Advanced Photon Source allowed the researchers to focus X-rays to unprecedented small dimensions.

The X-rays showed that, as the researchers repeatedly pulsed the device, progressively larger areas of the device ceased working, suggesting the atoms were switching structures less and less.

"After 50,000 switches, the atoms were stuck — they couldn't switch anymore," said Evans. A stronger electrical charge did put the atoms back in motion.

When the researchers used a higher voltage of electricity from the beginning, switching stopped 100 times later, as reported in the paper. And, in this instance, applying an even stronger pulse made no difference.

"With higher voltages, the material can't switch because something has changed about the material itself," said Evans. "When you use bigger voltages, it's not just the switching that stops working, but something even more fundamental."

Because previous researchers have not peeked inside working ferroelectric materials to understand their arrangement of atoms — key to the ability to recall information — reasons why switching eventually stops had not been clearly identified.

"The electronic memory is stored in the structure of atoms, and that's why it's so important to see what the structure looks like," said Evans. By looking inside these devices, he said engineers can begin to understand why the atoms stop switching, and then manufacturers can start to design better devices.

With this promise, Evans said, "Wouldn't it be nice to have a computer that doesn't forget what it's doing when you turn it off?"

Other researchers involved in the work include Chang Beom Eom (APS User), Dong Min Kim and the paper's first author, Dal-Hyun Do, from UW-Madison and Eric Dufresne from the University of Michigan.

Modifications to APS
water-supply system
will save $30,000 a year

Next to electricity, water is perhaps the most critical, and costly, ingredient needed to operate the technologically sophisticated Advanced Photon Source (APS) beam acceleration and storage complex. The Accelerator Systems Division Mechanical Engineering Group has begun a series of modifications to the accelerator water-supply system that is already realizing significant cost savings — with even greater savings to come.

The APS accelerator complex (including the linear accelerator, the booster, the radio frequency system and the storage ring) relies on a reliable, year-round supply of 10,000 gallons of specially processed, deionized and chilled water each minute to In order to control and reduce costs in this critical area, John Dench, Cheryl Fusco, Ric Putnam and Gene Swetin of the Mechanical Engineering Group revisited the design of the complex system of pumps that deliver water to the accelerators. The group decided to install override switches on the existing valves that control temperature, thus changing the pumping system from one of constant water volume to a more controlled, variable volume.

With the changeover about 60 percent complete, water flow to the accelerators has been decreased by more than 2,000 gallons per minute in the primary water-pumping loop that operates year-round. When modifications are completed at the end of 2004, water flow is expected to be reduced by a total of 3,000 gallons per minute. Additional savings will come from heavier use of low-cost water from the APS cooling tower, rather than water from the current higher-cost, two-stage system that uses tower water and then chilled water. Implementation costs of less than $2,000 are expected to save the laboratory more than $30,000 per year in energy costs.

Students explorescience,
technical careers via
videoconference link

By Elizabeth Quill

Instead of traveling on crowded school buses to Argonne-East, Chicago high school students are taking virtual field trips — stepping into the lab without leaving their desks.

The "Science Careers" series of video conferences conducted by Argonne, the Chicago Public Schools and the Chicago Workforce Board, exposes sophomore, junior and senior students to careers in science and technology.

"The whole idea is to get kids familiar with what it's like to be a scientist," said Fred Hartline of Argonne's Division of Educational Programs. "One of my pet peeves is that our education system doesn't really get kids prepared for, or aware of, the real world."

The program uses long-distance learning technology to connect students with scientists. During interactive "visits," students see what's going on in the lab and chat with researchers about scientific projects, the researchers' own educations and occupations in scientific fields. People from all over the laboratory have participated.

Scientists conducted the first conference last November from the Advanced Photon Source. Since then, there have been six more conferences.

George Shaw (CHM) and his colleagues spoke to the honors chemistry class at a Chicago high school in January. He said he wanted to share his work in photochemistry with students.

"We can't really take people into our lab, so we brought our lab to them," he said. "I really enjoyed it because I got a lot of feedback from the students. They asked insightful questions."

Hartline said the pilot program has proven successful. He works with schools to convince teachers that the program is worthwhile.

So far scientists have spoken mostly to honors and advanced placement classes, but there was a conference with a ninth-grade class.

"We can't do this one-size-fits-all," Hartline said. "We have to prepare differently depending on the context, the students and the timeframe."

Paula Moon (ES) spoke to an advanced placement chemistry class with two of her colleagues in June. The students had to design rockets that could land without breaking an uncooked egg. The students asked the scientists practical questions about their rocket designs and also personal questions about life as a scientist.

"We tried to introduce ourselves as down-to-earth people with families and hobbies and busy lives. I like camping and gardening," Moon said. "We want the students to know they don't have to spend all day thinking about science to be a scientist."

She said this is especially helpful in encouraging girls to enter the science field. Students need to know that scientists are real people and they can be scientists too.

"I believe in the importance of education and reaching out," she said.

Moon said she also likes to emphasize teamwork. Scientists don't work by themselves.

Hartline said he helps scientists communicate with teenagers on their level, because that can be difficult.

So far, the largest hurdles are technical. Participating schools need the infrastructure and bandwidth to achieve clarity in the video and audio signals.

Hartline said pilot programs inevitably have glitches, but the results are promising. He hopes the program grows.

"The point is to make the students aware of how exciting, involving and engaging a good career in science and technology can be," Hartline said. "Those students will eventually replenish the laboratory."

The Science Careers series is sponsored by the Illinois Department of Commerce and Economic Opportunity.

Volunteers are needed to participate in future sessions. Anyone interested should contact Hartline at ext. 2-5704 or fhartline@dep.anl.gov.

Health fair '04 to offer tests, screenings

"Health Fair 2004" will be held Tuesday, Sept. 14, giving employees a chance to interact with representatives from the laboratory's health-care vendors and companies providing health care services.

The Health Fair will be held from 11 a.m. to 2 p.m. in Argonne-East's Building 213 Cafeteria.

Services include chair massages, body fat measurements, computerized spinal tests, carbon monoxide testing, cardiovascular and diabetes screening (for a nominal charge), information on exercise programs and more.

The Health Fair is sponsored by Human Resources.

Professional development program
helps teach the science teachers

By Elizabeth Quill

This summer, 20 local K-12 teachers walked in their students' shoes for a month at Argonne-East.

The new and veteran educators participated in the Laboratory Science Teacher Professional Development Program, "Teachers as Investigators." The three-year program, part of the new science education initiative announced by U.S. Secretary of Energy Spencer Abraham in July, was designed to expand scientific knowledge and develop research experience among science and math teachers.

The teachers focused on three components: a research project, an education module and a professional development plan. The research topics focused on environmental chemistry and included soil and water composition and quality.

Teachers, accustomed to standing in front of the classroom, moved into the laboratory where they had to gather data, use unfamiliar instruments and procedures, get along in groups and, most importantly, learn.

Deon Ettinger (DEP), the program leader, said the projects emphasize inquiry-based learning, where students don't just read books and follow directions.

"So, we didn't give the teachers recipes. They faced all the same confusion that their students would face," Ettinger said. "It is highly likely that during an investigation they are going to get false starts and wind up following a tortuous path and have to overcome certain frustrations."

One group reshaped its project by finding real-world significance. Christopher Clausing, Jacqueline Maida, Debra McNabney, William Ness and Margot VanDyke dedicated their project to a town in downstate Illinois with three oil refineries and high rates of unusual cancers. Though they are not trying to link the refinery with cancer, they are taking soil samples in the northeast and southeast directions to see if there are differences in soil composition that may be attributed to wind direction.

The group used a gas chromatography-mass spectrometer and flame atomic absorption to test for organic and inorganic materials. Most teachers would not have access to these instruments in their schools.

Clausing was the only member who had experience with the instruments, so the teachers had to design flow charts and outline the process. At the end, the teachers were awarded a mini-grant they can use to purchase resources for their classrooms. Some will choose to buy less expensive versions of these advanced instruments such as hand-held probes.

"We are actually getting to feel what it's like to be a researcher, both the frustrations and the excitement," said Maida, who teaches at Homer Glen Junior High, Homer Glen.

The experience has prompted them to reexamine how to set up classroom labs. Not every lab table needs to get the same results and cookie-cutter experiments will not teach kids how science really works.

The team set up an education module to do soil testing using commercial soil testing kits. They also created project extensions, brainstormed science club activities and even envisioned a not-for-profit organization. They plan to stay together as a group and continue their research when they return to Argonne next summer.

"As a science teacher I need to know what science is," Clausing said. "We learn how to teach science, but not how science operates. We now know what is going on and we can teach it to our students."

Ettinger said after three years of work, totaling eight weeks, he hopes the program will graduate teachers who are better prepared to prime students for science fields in college and beyond. He said students entering college often become discouraged with science because they don't understand the process. These teachers will possess better tools to train future scientists.

More information on the new Department of Energy initiative, called Scientists Teaching and Reaching Students, is online.

Argonne Club planning Kankakee River canoe trip

The Argonne Club is planning a canoe trip down the Kankakee River Sunday, Aug. 29.

The 12-mile trip will last from three to five hours. Cost is $46 per canoe or double kayak. There is an additional $10 charge for a third person 12 years of age or older in each canoe or kayak. Single kayaks are also available for $36. The fleet will launch in the City of Kankakee.

Participants need to provide their own transportation to and from the event.

For more information, contact Christine Andorf (PBC-HP) at ext. 2-5153 or candorf@anl.gov.

Music, dance to mark U.S. Hispanic Heritage Month

To celebrate National Hispanic Heritage Month, the Argonne Hispanic/Latino Club will host performances at Argonne-East by Sones de Mexico and the Ensemble Español Spanish Dance Theater from Northeastern Illinois University.

Sones de Mexico will perform Wednesday, Sept. 15, from noon to 1 p.m., in the Building 362 Auditorium. The Chicago-based folk music ensemble plays many regional styles, including huapango, gustos, chilenas, son jarocho and the roots of Mariachi music, using a collection of more than 25 string, percussion and wind instruments
     The Ensemble Espaņol Spanish Dance Theater from Northeastern Illinois University will perform Thursday, Sept. 30, from noon to 1 p.m. in the Advanced Photon Source Auditorium.

The ensemble has "Professional In Resident" status and is one of the leading proponents of Spanish dance in the world.

CIS computer inventory now on sale

The Computing and Instrumentation Solutions Division is selling miscellaneous computer inventory, while items last, at prices below their original cost.

See "Inside Argonne" for a complete list of available items. A valid cost code is required to purchase.

The CIS Stockroom in Building 222, Room A253, is open from 8:30 a.m. to 4 p.m. Call the CIS Help Desk at ext. 2-9999 (option 2) for more information.

Employees of all skill levels
invited to fun run, walk

The Argonne Running Club will hold its monthly Fun Run and Walk Wednesday, Aug. 25, at noon.

The non-competitive event will start and finish at the Argonne-East Pool Pavilion, a few steps east of the pool.

All Argonne and U.S. Department of Energy employees and their guests of all skill levels are invited to participate.

Ice-cold refreshments will be served following the five-kilometer run and two-mile walk.

There is no fee to join in the event, but all participants will be required to sign in.

ISDN remote access
to be decommissioned

Computing and Instrumentation Solutions will decommission the ISDN remote access service Monday, Aug. 30.

With the introduction of newer high-bandwidth services such as DSL and cable, the number of ISDN users at the laboratory has decreased to only a few. CIS has recently reviewed ISDN system usage and its overall operational costs and found that it was time to retire this reliable but out-of-date service.

For more information about the ISDN decommissioning or assistance with selecting a high-bandwidth service such as DSL or cable, contact Mike Monczynski III (CIS) at ext. 2-4181 or mikemjr@anl.gov.

Ask the Directorate

Q. I am recently handicapped and find the walk on crutches from the handicapped spots in Building 201 to the elevators a very long walk, and this is followed by a second long hike after I reach my floor. These walks are very tiring for someone on crutches. It would be nice to have a couple of chairs or a sofa or bench at the elevators on each floor so that I could rest. The cost would be minimal and greatly benefit those who get tired with the long walks to their offices.

A. You will note that chairs have now been placed between the elevators on the first and second floors of 201, which we hope will provide a suitable resting point.

As for informal places to talk, we note that there is seating in 201 on the first floor near the coffee stand, the second floor around the corner from the elevators in procurement and opposite them near DOE, and on the third floor around the corner from the elevators. While the area on the first floor and near DOE on the second are some distance from the elevators, we trust they meet the needs of visitors.

For more information, see the Ask The Directorate Web site.

Employees can discuss
retirement plans, assets

The laboratory's retirement vendors will send representatives to Argonne-East during September to meet to answer employees' questions about retirement plans and retirement plan assets.

To schedule an appointment with these representatives, call the number listed. Appointments are for one-half hour each.

Prudential — Wednesday, Sept. 1, and Wednesday, Sept. 15. Mornings only. Call Cheryl at (847) 619-3519.

Fidelity — Tuesday, Sept. 7 and Tuesday, Sept. 21. Call the appointment desk at (800) 642-7131.

TIAA-CREF — Tuesday, Sept. 7, and Wednesday, Sept. 8. Call the appointment desk at (800) 842-2005 or visit the Web site.

MetLife quotes
offered on-site

A representative from MetLife Auto and Home will visit Argonne-East Tuesday, Aug. 24, to provide insurance comparisons and quotes for the "METPAY" group automobile and homeowners insurance program.

To schedule an appointment, call Craig Riddick at (630) 810-0346, ext. 143. Employees can also receive a quote over the phone by calling 1-800-438-6388.

CIS classes

"Advanced Word 2002" (CIS119) — Wednesday, Sept. 1, 8:30 a.m. - 4:30 p.m.

"Advanced Excel 2002" (CIS120) — Thursday, Sept. 2, 8:30 a.m. - 4:30 p.m.

"Advanced Access 2002" (CIS121) — Friday, Sept. 3, 8:30 a.m. - 4:30 p.m.

"Beginning Unix" (CIS564) — This class consists of two three-hour sessions. First Session: Tuesday, Sept. 21, 9 a.m. - noon. Second session: Thursday, Sept. 23, 9 a.m. - noon. No cost.

"Intro to viEditor in Unix" (CIS567) — Friday, Sept. 24, 9 a.m. - noon. No Cost.