Ab Initio Investigations of the Structural, Electronic, Magnetic and Mechanical Properties of Crx (X = As, Sb, Se, and Te) Transition Metal Pnictides and Chalcogenides

Abstract

The structural, electronic, magnetic, and mechanical properties of CrX (X = As, Sb, Se and Te) transition metal pnictides and chalcogenides were investigated using ab initio density functional theory using the local density approximation and generalized gradient approximation. Under ambient conditions, CrAs and CrTe are stable in the orthorhombic MnP (MP)-type antiferromagnetic (AFM) and hexagonal NiAs (NA) (FM) structures, respectively, whereas CrSb and CrSe have NA-type (AFM) structure. The half-metallic behavior was predicted for the zinc blende (ZB) and wurtzite (WZ) structures of CrAs, the zinc blende (ZB)-type of CrSb and CrSe compounds and the zinc blende (ZB) and rock salt (RS) structures of CrTe. However, the remaining structures are found to exhibit a metallic behavior. The highest total magnetic moment of 4 mu(B) was predicted for the RS and ZB (FM) structures of CrTe. The investigated CrX compounds were found to be mechanically stable at ambient pressure. The high value of B/G ratio indicates that CrSb (NA) is a ductile material, whereas CrAs (MP), CrSe and CrTe (NA) are brittle due to the lower B/G value.