Thermal transport in nano-engineered radiation-resistant silicon carbide

Collaborative Research Program 2023-2025

Proposed research pursues a fundamental predictive understanding of how phonon thermal transport and radiation resistance performance of nano-engineered silicon carbide (SiC) under high energy ion radiation can be controlled and used to design high-performance structural nuclear ceramics with enhanced radiation tolerance and heat transport for next-generation advanced nuclear reactors (NGANR). To reach this ultimate objective, we will employ advanced femtosecond laser-based time-domain thermoreflectance (TDTR) to conduct systematic investigations of nano- to micro-scale depth profiling of phonon-mediated thermal transport in ion irradiated SiC nanoengineered by chemical vapor deposition (CVD). Results of temperature-dependent thermal property measurements and structural characterization will be used to develop and validate our modeling via first-principles density-functional theory (DFT) calculations, large-scale atomistic simulations using the equilibrium molecular dynamics (EMD), and non-equilibrium molecular dynamics (NEMD) methods based on both the traditional (e.g. a hybrid Tersoff–ZBL potential) and latest machine-learning interatomic potentials, by semi-analytical defect-induced Klemens-Callaway phonon scattering modeling, and by continuum physics-based modeling. Special attention will be given to the investigation of ion fluence-, nanograin size- and temperature-dependent phonon thermal transport recovery due to annihilated radiation defects along the grain boundaries (GBs) and stacking faults (SFs) of SiC nanostructured by CVD.