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简介: |
Although the electrical transport property can range widely from superconducting to perfectly insulating in different materials, their thermal transport properties are confined in a relatively small range, which limits the performance of electronic, optoelectronic, and thermoelectric devices. Recently, we have carried out fundamental studies of the transport and coupling of thermal energy carriers including electrons, phonons, and magnons in different materials in order to search for new approaches to achieving extraordinary thermal properties. Highly sensitive micro-fabricated devices are invented to probe size-dependent phonon transport in one-dimensional and two-dimensional hexagonal structures as well as three-dimensional cubic boron arsenide with potentially record high thermal conductivity. Inelastic neutron scattering is employed to understand the intriguing phonon and magnon dynamics of complex incommensurate crystals with low lattice thermal conductivity or high magnon thermal conductivity. Inelastic light scattering experiments are further designed to probe the remarkably long relaxation lengths of phonons and magnons in some hexagonal and magnetic materials, respectively. The findings from these basics studies are used to guide the search of materials with ultrahigh or ultralow thermal conductivity, increased thermoelectric figure of merit, or enhanced spin caloritronic properties.
Biography:
Li Shi is the BF Goodrich Endowed Professor in Materials Engineering at The University of Texas at Austin. He was an IBM Research Staff Member for a year before joining the faculty at UT Austin in 2002. He received his PhD, MS, and BE degrees from University of California at Berkeley, Arizona State University, and Tsinghua University, respectively. Dr. Shi currently serves as the Editor-in-Chief of Nanoscale and Microscale Thermophysical Engineering. His scholarly work has been recognized by the CAREER Award from the US National Science Foundation, the Young Investigator Award from the US Office of Naval Research, the O’Donnell Award in Engineering from The Academy of Medicine, Engineering, and Science of Texas, and the Invitation Fellowship for Research in Japan by Japan Society for the Promotion of Science. He is an elected fellow of American Physical Society (APS) and American Society of Mechanical Engineers (ASME). |
