Structural, electronic and magnetic properties of the Half-Heusler alloy CrZSi (Z = Sc, Ti)

Abstract

The structural, electronic and magnetic properties of the half-Heusler alloys CrZSi (Z = Sc, Ti) were studied using Density Functional Theory (DFT) based on pseudopotential method to explore the Cr-based ferromagnetic half-metallic alloys. The effect of substitution of scandium and titanium in Slater-Pauling behaviour, half-metallicity and mechanical properties were studied to understand the role of low valent transition element in half-Heusler compound. CrTiSi shows half-metallicity with an indirect bandgap of the value 0.765 eV. The robustness of half-metallic behaviour at different hydrostatic pressures were calculated. CrTiSi obeys Slater-Pauling rule and has integer magnetic moment of 4 μB. The mechanical properties were studied for both CrScSi and CrTiSi compounds to obtain elastic constants and moduli. The present work reveals the ductile nature of the compounds as their B/G ratio is >1.75 with positive Cauchy pressure. Further, phonon calculation with absence of negative frequencies determines the dynamical stability of the compound.