Thermal transport recovery in irradiated SiC mediated by nano-layered stacking faults

We investigate phonon thermal transport and resistance to ion irradiation in nanostructured 3C-SiC using molecular dynamics (MD) simulations. Two-dimensional planar defects in the form of stacking faults (SFs) spaced within nanometer-scale vicinity from each other promote healing of both: radiation-induced point defects (PDs) and thermal conductivity (k) under 10 keV Si ion irradiation number of displacements per atoms (DPA= 0.0016 – 0.034). With the rise of DPA below the onset of amorphization, the decay in k due to PDs and SFs is found to be less rapid than that due to the presence of only PDs. Observed relative recovery of heat conductivity is due to enhanced recombination of Frenkel pair PDs spatially confined between neighboring SFs, as confirmed by collision cascade MD simulations. Calculations from the Boltzmann transport equation combined with the Klemens model are consistent with findings from MD simulations. The interplay between enhanced PD recombination and thermal transport recovery is observed for different types of SFs. Obtained results pave the way to guide the design of nano-engineered nuclear ceramics with simultaneously enhanced radiation tolerance and heat conductive properties.