Dr. William J. Weber, Professor Emeritus of Materials Science & Engineering Department, University of Tennessee will give a seminar titled "Effects of Electronic Energy Loss on Damage Production and Evolution in Ceramics" to the interested faculty and students at Discovery Park.

Abstract

The interaction of ions with solids results in energy loss to both atomic nuclei and electrons in the solid. Using experimental and computational approaches, we have investigated the separate and combined effects of nuclear and electronic energy loss on the response of ceramics to ion irradiation over a range of energies. Experimentally, ion mass and energy are used to control the ratio of electronic to nuclear energy loss; whereas, large scale molecular dynamics simulations, which include ballistic collision processes and the inelastic thermal spike from ionization, are used to model these effects. Using these approaches, we demonstrate additive effects of nuclear and electronic energy loss on damage production and grain growth; competitive effects via ionization-induced damage recovery; synergistic effects on damage production; and a cross-over effect from synergistic to competitive in ion-irradiated ceramics. These results have significant implications for the response of materials to extreme radiation environments and ion beam modification of materials to produce novel defect structures, nanostructures and phase transformations that tailor chemical and physical properties or create new functionalities within materials.

Bio

Dr. William J. Weber joined faculty in the Department of Materials Science and Engineering at the University of Tennessee in May 2010 as the Governor’s Chair Professor in Radiation Effects in Materials, with a joint faculty appointment at Oak Ridge National Laboratory. He also serves as director of the Ion Beam Materials Laboratory at the University of Tennessee. He received his B.S. (cum laude) in Physics from the University of Wisconsin, Oshkosh in 1971, and his M.S. and Ph.D. in Nuclear Engineering from the University of Wisconsin, Madison in 1972 and 1977, respectively. His dissertation research was on the temperature dependence of void and dislocation loop formation in ion-irradiated vanadium. From 1977 to 2010, he was at Pacific Northwest National Laboratory (PNNL) where he conducted research on radiation effects in ceramics and glasses, the long-term behavior of nuclear waste forms, electronic and ionic transport in ceramics, solid oxide fuel cells, high-temperature superconductors, and physics of radiation detectors. He was appointed Laboratory Fellow in 1997 and served as Chair of the PNNL Council of Fellows from 2005 to 2009. In 1983, he was a visiting scientist at the Institute for Transuranium Elements in Karlsruhe, Germany, where he studied radiation effects in actinide compounds, nuclear waste glasses, and nuclear fuel materials. From 1989 to 1993, he was on a special assignment to the Office of Basic Energy Sciences, US Department of Energy, where he provided technical assistance in the review and evaluation of materials sciences programs. Dr. Weber has authored or co-authored 14 book chapters and over 725 peer-reviewed papers with more than 31,400 times. He has given over 255 invited presentations at national and international scientific conferences, workshops, research institutions, and universities.