Strain effects on the lattice thermal conductivity of monolayer CrOCl: A first-principles study

Abstract

Monolayer CrOCl is an intrinsically ferromagnetic two-dimensional semiconductor material with potential applications in nano-spintronic devices, which call for fundamental studies of phonon transport. Here, we investigate the lattice thermal conductivity of monolayer CrOCl under uniaxial strain using first-principles calculations to solve the phonon Boltzmann transport equation. At 300 K, the lattice thermal conductivities of monolayer CrOCl are 47.00 Wm−1K−1 (x direction) and 123.97 Wm−1K−1 (y direction), exhibiting significant anisotropy. Applying uniaxial strains of − 2–2% to monolayer CrOCl in the x and y axes, we discovered that both compressive and tensile strains reduced the thermal conductivity of monolayer CrOCl. By analyzing the responses of heat capacity, phonon group velocity, and phonon lifetime to strain, we determined that the rapid decrease in phonon lifetime under strain is the primary cause of the decrease in thermal conductivity.