Studying Entropy in Metallic Glasses
Brent Fultz, Barbara and Stanley R. Rawn, Jr., Professor of Materials Science and Applied Physics, and colleagues have pinpointed that arrangement of atoms is the main source of an increase in entropy during the glass transition. One persistent mystery about metallic glasses occurs at the so-called "glass transition." A cold metallic glass is hard and brittle, but when it is heated past a certain point—the glass transition—it becomes soft. [Caltech story]
Professor Minnich Receives IPPA Junior Prize
Austin Minnich, Professor of Mechanical Engineering and Applied Physics, is a recipient of the International Photothermal and Photoacoustics Association (IPPA) Junior Prize. He received the prize for outstanding contributions to the understanding of quasiballistic thermal transport, including the development of photothermal methods to directly probe heat conduction at length scales comparable to phonon mean free paths; for demonstrating how microscopic transport properties of thermal phonons in solids may be obtained using photothermal experimental methods along with ab-initio calculations; and for advances in the mathematical treatment of quasiballistic transport using the Boltzmann equation.
Andrei Faraon, Assistant Professor of Applied Physics and Materials Science, and colleagues have discovered how to use computer-chip manufacturing technologies to create the kind of reflective materials that make safety vests, running shoes, and road signs appear shiny in the dark. The new technology uses surfaces covered by a metamaterial consisting of millions of silicon pillars, each only a few hundred nanometers tall. By adjusting the size of the pillars and the spacing between them, Faraon can manipulate how the surface reflects, refracts, or transmits light. [Caltech story]