Unveiling the role of atomic defects on the electronic, mechanical and elemental diffusion properties in CuS

Abstract

Effects of atomic defects on electronic properties, mechanical stability, and elemental diffusivity in CuS (or covellite) were investigated by first-principles calculations. The metallic CuS shows higher structural and mechanical stabilities compared to CuxS phases. Strong covalent bonds in pristine CuS restrict the self-diffusion of Cu and S atoms; however, different band orientations in presence of atomic vacancies result in a high degree of self-diffusion. Specially, sulfur vacancies play a prominent role in increasing the diffusion of both Cu and S. Calculated self-diffusion coefficients between 100 °C and 150 °C are of the order of 10−6 cm2/s, comparable to experiments.