TMS 2007: Lectures

Hume-Rothery Award Lecture

Topic: "How Big is an Atom?"
Date: Monday, Feb. 26

While atomic size mismatch and electron/atom ratio (e/a) are determinants in phase stability, unavailable in Hume-Rothery’s day, experimental, theoretical and computational methods have made enormous progress possible.

Professor Moss will discuss atom size in material and its determination, along with standard crystallography, through diffuse scattering at the national synchrotron and neutron scattering facilities, and at his in-house x-ray lab. The topics cover metallic alloys, semiconductor III-V films and multilayers, oxides, and glasses, where local size plays an often nonintuitive role.

Studies range from the Fe-C dipole distortion in martensite, to the interfacial strain in thin III-V multilayers, to local size effects in alloys with a very small mismatch (Fe-Cr) and an appreciable mismatch (Ni-Pt vs, CuAu). Also explored are the O-vacancy-induced modulations in YBCO and the rapidly diffusing Au in Pb, all variants on the same theme of “size.”

This lecture is supported by DOE/BES, NSF/DMR, and the State of Texas.

SPEAKER

SIMON C. MOSS Professor Univ. of Houston

Simon C. Moss is the M.D. Anderson Professor of Physics at the University of Houston in Texas, where he has spent more than 30 years of his career. His doctorate is in metallurgy and materials science.

Professor Moss is a member of the Materials Science Review Committee for Brookhaven National Laboratory. He has more than 200 publications to his credit and received more than a dozen honors and awards.