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AWARD-WINNING UH PROFESSOR SELECTED TO ORGANIZE ALLOYS SYMPOSIUM
Simon Moss Receives William Hume-Rothery Award for Furthering the Science of Alloys
HOUSTON, June 15, 2005 As the recipient of the 2007 William Hume-Rothery Award from The
Minerals, Metals, and Materials Society (TMS) for his leadership and contributions to the
science of alloys, a University of Houston professor has now begun organizing the
accompanying symposium for the 136th TMS Annual Meeting & Exhibition in 2007.
In addition to being invited to arrange the Hume-Rothery Memorial Symposium held in
conjunction with the annual meeting Feb. 25 through March 1, 2007, in Orlando, Fla., Simon
C. Moss, M.D., Anderson Distinguished Professor of Physics at UH, will give a keynote
address and present a paper.
TMS is the professional society whose mission is to promote the global science and
engineering professions concerned with minerals, metals and materials. Given annually, the
William Hume-Rothery Award was established in 1972 by TMS to honor the memory of the great
pioneer in alloy phases William Hume-Rothery, who was an Oxford professor and the leading
figure of his time on the physics of alloys.
It makes me very happy to receive this award, this affirmation from my peers, Moss said.
I am already planning what I would like to talk about and who I would like to invite to
present papers around selected topics, both experimental and theoretical. I will definitely
talk about Hume-Rothery and how his work has played out in contemporary science and in my
own work.
Alloys are metals, such as steel and brass, composed of more than one element, where the
resulting material has metallic properties and certain specific desirable characteristics,
including strength, formability and corrosion resistance. Their use is ubiquitous, and a
fundamental understanding is essential. In the 1960s, three scientific papers published by
Moss and his collaborator, Philip C. Clapp, tied together their groundbreaking work on the
local structure of (nominally) disordered alloys with regard to the energies of interaction
among the atomic species that control the diffuse scattering of X-rays and neutrons that may
be retrieved from such measurements.
There is always a competition in matter between the states in which atoms are either
arranged as largely ordered or essentially random, Moss said. We knew that in alloys, high
temperature and disorder go together. The missing link was the ability to assess the
energies that determine the structure. This is important because the scattering of X-rays or
neutrons from the high-temperature disordered state may be the sole direct method to access
these energies that are crucial for alloy formation and stability. Of course, always at high
temperature, entropy, or disorder, will eventually prevail over the energy and will disorder
the atoms in alloys.
A prominent example that uses only the sharp Bragg peaks and not the distributed diffuse
scattering is the local structure of carbon in iron (i.e. steel). From his measurements,
Moss was able to determine the very distorted local region around a carbon atom that
accounts for the basic strength of carbon steels. Without carbon, iron is nearly as soft as
butter. Another very recent example demonstrated that the structure of the UH
high-temperature superconductor, YBa2 Cu3 O6.93 (YBCO), is really constituted of very
short-range atomic modulations.
Redefining the field of alloy studies, the Clapp-Moss theory became known as
Krivoglaz-Clapp-Moss (KCM) Theory named for Clapp, Moss and M.A. Krivoglaz, the great
Russian theorist whose earlier work in this area was combined with theirs. The correlation
functions in disordered systems via KCM Theory is a topic still continually updated by
prominent theorists.
Today, using the scattering techniques noted above, Moss continues to study the atomic
structure of alloys in order to understand their phase stability and properties. Currently,
he is working with Wolfgang Donner, an assistant professor of physics at UH, on several
projects, including one that details the local structure of the very thin oxide film on
silicon that turns out to be quite different from the bulk glass and is critical in the
designing of computer chips. Donner has followed this thread in his own work, examining the
growth of metallic multi-layer thin films, in an apparatus he built in his lab, that are
used in magnetic recording. Moss and his colleagues, including Miguel Castro-Colin, a UH
post-doctoral fellow whose dissertation was on this topic, recently published two definitive
papers on the, presumably disordered, glass of silicon dioxide. Castro-Colin will take up an
associate professorship at the University of Texas at El Paso this fall, where he will
continue to pursue this challenging line of research.
Joining UH in 1972, Moss received his bachelor and masters degrees in metallurgy from the
Massachusetts Institute of Technology in 1956 and 1959. He earned his doctorate in
metallurgy and materials science from MIT in 1962, in the lab of the pre-eminent MIT
Physicist B.E. Warren, working on the scattering from disordered materials. Receiving many
honors and awards since, Moss has served on a number of editorial and advisory positions
both on professional journals and on panels for the Department of Energy, the National
Academy of Sciences and several national neutron scattering centers.
Contact: Lisa Merkl
713/743-8192 (office), 713/605-1757 (pager)
UNIVERSITY OF HOUSTON
Office of External Communications
Houston, TX 77204-5017
Fax: 713/743-8199
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