Nano- and micro-scale phonon-mediated thermal transport in ion irradiated and nanostructured solid-state materials

Understanding heat conduction on micro- and nano- meter spatial scales in solid-state materials is very important for thermal management encountered in numerous applications involving, but not limited to, nuclear and fission energy, thermoelectric, electronic and opto-electronic devices. We will review our recent results on phonon-mediated thermal transport in various solid-state systems: (1) swift heavy ion irradiated single crystalline metal oxides and alkali halides, (2) irradiation-assisted phase-transformed single crystalline Ga2O3, (3) ion irradiated and nano-crystalline SiC, and (4) nano-porous & nano-granular Si. Conducted studies employed several laser-based thermal metrology techniques ranging from femtosecond laser-based time-domain thermoreflectance to continuum wave laser-based frequency- and spatial-domain thermoreflectance and micro-Raman opto-thermal spectroscopy, as well as molecular dynamics and semi-analytical phonon thermal transport calculations. New results revealed intriguing heat propagation phenomena associated with the presence of point and extended defects, heat conductivity recovery in irradiated nano-crystalline ceramics, thermal anisotropy and nanoscale phonon hydrodynamics.

Speaker's bio:
Dr. Zhandos Utegulov is an Associate Professor and Director of Advanced Materials Research & Laser Technologies (AMRELAT) Laboratory in the Department of Physics of School of Sciences & Humanities of Nazarbayev University in Astana, Kazakhstan. Prior to Nazarbayev University he held research appointments at Idaho National Laboratory, University of Nebraska- Lincoln, National Institute of Standards and Technology in Boulder, Colorado and University of Cincinnati. He obtained his PhD in Physics from Oklahoma State University in 2003.
His research group is involved in laser-based material science & optical sensing development with the focus (1) nano- and micro-scale thermal transport in ion irradiated, nanostructured, interfacial and phase-transformed materials by advanced optical measurements and atomistic modeling techniques, (2) spatially–resolved elastic properties of irradiated solids and visco-elastic properties of soft matter by Brillouin light scattering spectroscopy and (3) high temperature thermophysics of nanosecond pulse laser-driven melting measurements by laser acoustics & molecular dynamics simulations.