Frank Spedding and Harley Wilhelm, Ames
Laboratory co-founders, would have been pleased to see how the
old and the new came together for two lighthearted hours May 16
as employees, past and present, celebrated Ames Lab's 50th
anniversary. Whether viewed through the expectant eyes of young
graduate students or the earnest eyes of time-honored retirees,
the festivities offered an opportunity for generations of
employees to unite in recognition of a half-century of excellence
and commitment to science within the Ames Lab community.
The Materials Sciences Award for "Sustained Outstanding Research" in solid state physics went to Cai-Zhuang Wang and Kai-Ming Ho for developing a new technique for simulating the dynamics of large systems of covalently bonded atoms (on the order of 10,000 or more). Covalently bonded atoms share electrons, forming a chemical bond between the atoms.
The technique, called
tight-binding molecular dynamics (TBMD), bridges the gap between
the two conventional methods of studying interatomic
interactions, which lack either the speed or the accuracy
necessary for efficient and cost-effective study of larger
systems.
Wang and Ho have performed extensive TBMD computer simulations to study the structures, dynamics and electronic properties of complex silicon and carbon systems. "We've investigated the structures of fullerenes (cages of carbon atoms) from C20 to C100," says Ho. "Usually people can do a couple of structures with traditional methods, but it would be quite expensive to do the whole range. Furthermore, for a given cluster size (for example, C84), there are lots of ways you can put the atoms together to form a cage."
"We've actually predicted the ground state structure for C84 using TBMD, and the results have subsequently confirmed by experiment," says Wang.
TBMD has also proven a valuable technique for studying complicated systems involving large numbers of atoms, such as amorphous and liquid phases, as well as crystalline defects.
Ames Laboratory received its second
Materials Sciences Award as a result of a unique collaboration
with the Idaho National Engineering and Environmental Laboratory
(INEEL) in Idaho Falls, ID. The partnership led to an award in
metallurgy and ceramics for both organizations in the category of
"Significant Implication for Department of Energy (DOE)
Related Technologies."
Bill McCallum, Matthew Kramer and Kevin Dennis of Ames Laboratory collaborated with Daniel Branagan, Timothy Hyde and Charles Sellers of INEEL. The team developed a means of controlling the solidification process of rare-earth permanent magnets during rapid solidification and then used it to tailor an alloy for gas atomization. The partnership was part of the program for Tailored Microstructures in Permanent Magnets, sponsored by the DOE Center of Excellence for Synthesis and Processing of Advanced Materials.
In an unusual but fortunate twist, an exchange of personnel further advanced the award-winning research when Branagan completed his PhD with McCallum at Ames Laboratory and then took a position with INEEL. Branagan's work with McCallum and the basis of his doctoral thesis had been to investigate what might be called "model" rare-earth-based permanent magnet systems; in particular, pure neodymium-iron-boron (Nd2Fe14B) doped with titanium carbide (TiC), from a fundamental standpoint.
"Typically, when people are looking at permanent magnets, they start from the best material and try to improve it," says McCallum. "The problem with that is the best material is quite complex, so when you try to make improvements, it's difficult to tell just exactly what each change you make is doing."
To avoid that dilemma, McCallum and Branagan intentionally designed a model alloying process to allow the change of only one particular factor -- the means of controlling the grain size or microstructure, which, in turn, leads to significant improvements in hard magnetic properties and a reduction in processing costs for permanent magnets.
At INEEL, the concepts resulting from Branagan's thesis research with McCallum have been applied to technically useful compositions with potential impact for better magnets that will allow more energy-efficient motors for industrial, automotive and consumer applications.
"The results of INEEL's work have been fed back to us, which has had a profound impact on our understanding of how the microstructure develops," says McCallum. "Their work has allowed us to expand our fundamental understanding substantially. What Ames Lab and INEEL have done is not something that says we're going to make a better permanent magnet -- what it says is that we can make a good magnet much more easily."
A partnership science education program between Ames Laboratory and a local elementary school resulted in an unexpected honor for Suzanne Kelly, a fifth-grade teacher at Meeker School in Ames. She was selected as the one elementary school science teacher in the United States to receive the National Catalyst Award -- a teaching award for contributions to science education from the National Chemical Manufacturers Association.
Kelly was nominated for the award by Scott Chumbley, an Ames Lab metallurgist and an Iowa State University (ISU) associate professor of materials science and engineering. Kelly worked with Chumbley on the Teacher Education and Achievement in Math and Science (TEAMS) Program, which links Ames Lab scientists and ISU education students with elementary school classrooms in an effort to bring practical science experiences to students.
The students in Kelly's classroom gained knowledge of real-world chemistry processes through such innovative activities as setting up imaginary chemical research companies and doing experiments for the companies they created. Extending the project, they even made company mottos and identification badges.
As part of the Lab's TEAMS Program, Chumbley and Kelly also developed a book of simple science labs and activities that can be used by elementary school teachers. "I believe very strongly in hands-on science," says Kelly. "These labs teach the process and skills the students need."
Noting that the National Catalyst Award also recognizes the cooperation between educators and businesses to support education, Kelly adds, "The Ames Lab TEAMS Program is a good example of how schools can do more with expert help."
Pat Thiel, Ames Laboratory program
director for Materials Chemistry, has been invited to serve as a
member of the DOE's Basic Energy Sciences Advisory Committee. She
was appointed by Secretary of Energy Frederico Pena on April 17.
The Basic Energy Sciences Advisory Committee reports to the director of the Office of Energy Research and provides significant advice to the DOE on policy issues, long-range plans, priorities, and strategies relating to the national Basic Energy Sciences (BES) Program. In FY97, 69 percent of Ames Lab's $27 million DOE budget was directly funded through the BES program. The BES Program anticipates funding research for FY98 at approximately $431 million to DOE labs nationwide, so the expertise and counsel provided by the BES Advisory Committee members have a major impact on science in the U.S.
"The opportunity to serve on the BES Advisory Committee will be a valuable experience in learning more about the inner workings of the BES Program," says Thiel. "My mission will be to bring to the Committee views of basic energy sciences focused on surface science."
"The BES Advisory Committee is a very prestigious group," says Bruce Thompson, former Ames Lab division director for Science and Technology. "They advise DOE on a wide range of science issues having to do with how we conduct the basic research that forms the foundations for the various activities of the Department of Energy. It's a real credit to Dr. Thiel and to Ames Lab that she was selected to be a Committee member."
David Jiles, senior physicist,
accomplished the almost impossible task of adding a new group,
the Topical Group on Magnetism, to the American Physical Society
(APS). The new group made its debut at the APS meeting in Kansas
City, MO, in March. The magnetism group has 361 members and is
growing rapidly at a rate of 25 per month. "There was a
marked increase in interest in magnetism at this year's meeting,
which probably reflects the rapid upswing in interest in
magnetism and magnetic materials in the last couple of
years," says Jiles.
Return to Inquiry table of contents
Last revision: 4/17/98 sd
Home | Comments | Search | Disclaimer