Exploring the energy landscape and crystal structures of CrSi2N4

Abstract

AbstractThe Cr−Si−N system is of great interest for materials with advanced tribological and mechanical properties. So far, experimental data have been reported on Cr−Si−N coating, nanocrystalline phases, and thin films, together with theoretically predicted 1D and 2D hetero‐structures, and 3D bulk Cr2SiN4 modifications. This study predicts possible bulk Cr−Si−N phases with the composition CrSi2N4. A multi‐methodological approach has been employed to explore the system's energy landscape, where global optimization was combined with data mining and the Primitive Cell for Atom Exchange (PCAE) method. Local optimization of the structure candidates was performed on the DFT level using the GGA‐PBE and the LDA‐PZ approximation. The ten energetically most favorable structure candidates discovered in the CrSi2N4 chemical system mostly exhibited monoclinic symmetry but with a variety of structural features, from zeolite‐like structures to polytypic behavior. Finally, the bulk modulus of these possible modifications was computed for a pressure range of up to 10 GPa.