Theoretical investigations of physical properties of Pt-based half-Heusler alloys PtMnZ (Z = Se, Sn, Te) for spintronic applications

摘要

The structural, mechanical, thermal, electronic and magnetic properties of Pt-based half-Heusler alloys XYZ (X = Pt, Y = Mn, Z = Se, Sn, Te) are determined using FP-LAPW method based on density functional theory (DFT). The exchange-correlation potential is treated with the generalised gradient approximation described by Perdew-Burke-Ernzerhof (PBE-GGA), GGA plus band correlated Hubbard parameter (GGA + U) approximations. Structural results reveal that the PtMnZ half-Heusler alloys (Z = Se, Sn, Te) have metallic character. The negative values obtained for formation energies confirm that our compounds can be synthesised and stabilised experimentally ensuring the stability of these compounds, which is confirmed too by the results of mechanical properties. The thermodynamic ones are also studied through Debye quasi-harmonic model such as Debye temperature and the heat capacity. The calculated electronic properties unveil the metallic nature of the studied compounds. The computed magnetic properties reveal that the total magnetic moment is mainly emanated from the transition metal element. Results suggest that PtMnZ (Z = Se, Sn, Te) compounds are promising candidates for spintronic devices.