Brent Fultz, Rawn Professor of Materials Science and Applied Physics

    Fundamental materials physics and materials chemistry, with a view towards energy applications.

 

 

    Brief Biography and Research Summary


Brent Fultz received his undergraduate degree from MIT, and his Ph.D. from U. C. Berkeley in 1982. He was a Presidential Young Investigator, he received an IBM Faculty Development Award, a Jacob Wallenberg Scholarship, and won the TMS EMPMD Distinguished Scientist Award in 2010. Brent Fultz has been announced as the winner of the 2016 William Hume-Rothery Award of TMS. He serves on review boards of the Advanced Photon Source and the NIST Center for Neutron Research. He consulted for an electronics testing company, Everett Charles Technologies, for the Defense Science Board, was a member of the Science Advisory Board of Actium Materials and Contour Energy, and is now on the Science Board of the Materials Project. Fultz has authored or co-authored over 390 publications.


With his friend, Prof. J. Howe of Univ. Virginia, Fultz published a graduate-level textbook on diffraction and microscopy of materials (now in its fourth English edition, first Russian edition, and under translation into Chinese). More recently, Fultz authored a graduate-level textbook on phase transitions in materials that unifies concepts from traditional materials science and from condensed-matter physics.

X-ray and neutron scattering are two of the most important methods for studying materials, and the U.S. community scattering scientists has access to remarkably powerful and precise synchrotrons and neutron sources. These require innovative hardware and software for new studies of materials. Brent Fultz was the Principal Investigator of the ARCS spectrometer project at the Spallation Neutron Source, now complete and in operation. Scientific computing offers opportunities for doing new science with neutron scattering experiments, and Brent Fultz was the Principal Investigator of the software project Distributed Data Analysis for Neutron Scattering Experiments, DANSE . A new effort on computational scattering science is underway, and descriptive reports are available for download on this website.

One topic of Fultz's research is how atom vibrations in solids affect the entropy and thermodynamic stability of materials -- a review article is available here (4.5 MB). Vibrations are the main source of entropy of solid materials. They are quantized as "phonons," which we measure by inelastic neutron scattering. Inelastic neutron scattering is also sensitive to magnetic and electronic excitations in solids, and these excitations can have thermodynamic importance, too. Most of scientific challenge for us is identifying the reasons for differences in phonon entropy of different materials, and how the phonon entropy changes with temperature and pressure. Recent work has focused on behavior over a broad range of temperature, where phonons interact with other phonons, and with electronic excitations.

Modern ab initio computations based on density functional theory are now essential for this work on phonons and electrons in solids. For efficiency in understanding the contributions to thermodynamics, high pressure research is generally easier by computation, and high temperature work is generally easier by experiment. Nevertheless, at high temperatures, the quasiparticle excitations of phonons and electrons can be studied computationally by ab initio molecular dynamics. Using high-resolution inelastic x-ray scattering, Fultz's group has also been measuring how vibrational thermodynamics is altered when the material is under megabar pressures in a diamond anvil cell.

The global "energy problem" is of paramount societal importance, and of some urgency. Research on energy-storage materials can help. For many years Fultz's group has worked on materials that store lithium (used in rechargeable batteries), and on materials that store hydrogen. One effort is focused on understanding the interactions of hydrogen molecules with surfaces, with the goal of learning how to optimize the hydrogen-storage potential of new materials that store hydrogen by adsorption interactions. For materials that store lithium or sodium ions, Fultz's group found an opportunity to use nuclear resonant scattering on materials at sub-megabar pressures to measure the atom distortions that occur as an electron hops between adjacent ions. The mechanism of "small-polaron hopping" is the source of electrical conductivity of many battery materials that are otherwise insulators at low temperatures. Understanding polaron dynamics should open possibilites for many more electrode materials in rechargeable batteries.

Brief descriptions of recent research results are given in the Fultz Group site. Fultz's interview for the Distinguished Scientist Award, with thoughts for young scientists, is here.