Simon Charles Moss

Simon Charles Moss, one of the world’s foremost authorities on using x-ray and neutron scattering as probes of order and disorder in matter, died of a heart attack at his home in Houston, Texas, on 14 March 2011. At the time of his death, he was emeritus professor of physics at the University of Houston, where for many years he had been the M. D. Anderson Distinguished Professor of Physics.

Born in Woodmere, New York, on 31 July 1934, Simon received his bachelor’s and master’s degrees in metallurgy from MIT in 1956 and 1959, respectively. In 1962, working in the lab of preeminent MIT physicist B. E. Warren, he earned his doctorate in metallurgy and

materials science for research determining atomic-scale structures of disordered materials from their x-ray scattering. Simon taught in the department of metallurgy and materials science at MIT before traveling to Melbourne, Australia, as a Guggenheim Memorial Foundation fellow for 10 months during 1968–69. In 1970 he and a small group of colleagues from the Boston area went to Troy, Michigan, to work for Energy Conversion Devices, a small company founded by Stanford Ovshinsky. There, Simon brought in Nevill Mott, David Turnbull, Morrel Cohen, John Cahn, and many other luminaries as consultants.

Ultimately, Simon preferred to return to a university, and the idea of helping to build up a physics department in Houston appealed to him. In 1972, influenced by Melvin Eisner, he joined the University of Houston physics department. There he found his niche, doing innovative research on the full gamut of materials from heterostructures and multilayers to quasicrystals and decagonal crystals. He studied fullerenes; ordered and disordered metallic alloys; oxide superconductors, glasses, and liquids; amorphous semiconductors; and more.

Simon’s early research on correlation functions of disordered binary alloys made a major impact on the field. During the 1960s Simon and his colleague Philip Clapp published three scientific papers on their groundbreaking studies of the local structure of disordered alloys as a function of the energies of interaction among atomic species. Ultimately redefining the field of alloy research, the Clapp–Moss theory became known as the Krivoglaz-Clapp-Moss theory, which added the work of Mikhail Krivoglaz, the great Russian theorist. Even today prominent theorists continue to update the correlation functions in disordered systems via the theory.

Atomic-scale disorder continuously fascinated Simon. During the 1980s he extended his earlier experimental and theoretical work on disordered materials to low-dimensional structures. One heroic result of his research during that period was the achievement, in collaboration with colleague George Reiter, of what became known as the Reiter–Moss theory—a theoretical understanding of two-dimensional liquids modulated by the underlying substrate.

Simon’s brilliance and his sharp wit were particularly apparent in scientific discussions. He profoundly influenced a generation of young German scientists during his annual summer stays in Munich. His deep insight into order and disorder in matter and his ability to tease information from the subtleties of diffraction patterns are legendary. For his work he received wide recognition, including the American Physical Society’s David Adler Lectureship Award in 1993 and the Minerals, Metals, and Materials Society’s William Hume-Rothery Award in 2007. The Materials Research Society bestowed the 2001 Von Hippel Award on Simon “for consistently timely and essential contributions to identifying and understanding the atomic-level structure of almost every new type of material discovered in the last thirty years.”

Simon was larger than life. He was a superb experimentalist, but he also deeply understood theory and sympathized with theorists. He was a man with many talents and interests, a good travel companion, a dangerous driver, a bon vivant who had to give up fine wines, a splendid athlete despite teenage polio until struck by secondary polio. He was an avid art collector and a lover of ballet, classical music, opera, poetry, and tennis.

In recent years he had become very frustrated with his physical limitations, but his extraordinary mental capacity never diminished. The physics world has lost one of its most influential researchers in disordered and defective solids and thin films. His lasting legacy lies with the many scientific colleagues, successful students, and postdoctoral associates he influenced over the course of his exceptional career.