First-principles computation of new series of quaternary Heusler alloys CoScCrZ (Z = Al, Ga, Ge, In): a study of structural, magnetic, elastic and thermal response for spintronic devices

Abstract

Various physical properties of CoScCrZ (Z = Al, Ga, Ge, In) Heusler alloys (HAs) are examined using full potential linearised augmented plane wave (FP-LAPW) method within framework of density functional theory (DFT). The calculated structural parameters show that, the ferromagnetic (FM) phase is the most stable. The calculated elastic constants indicate that all alloys are mechanically stable and have ductile nature. The band structures (BS) and density of states (DOS) of all HAs revealed the half metallic (HM) nature with 100% spin polarisation (SP). The presence of band gap (BG) in minority spin state is due to d-d hybridisation among transition metals. The calculated magnetic moments (MM) are in accordance to Slater-Pauling rule (SPR). The partial DOS results show that the major contribution in MM belong to Co and Cr atoms. The Curie temperature (Tc) and SP are also calculated. The thermoelectric properties i.e. Seebeck coefficient (S), electrical and thermal conductivity are calculated and discussed. These HAs are being reported first time; therefore, no experimental or theoretical data is available for comparison. The obtained results such as HM nature, complete SP, mechanical stability, and adequate S make these HAs available as potential candidates for spintronic and thermoelectric devices.