Robust stability, half-metallic ferrimagnetism and thermoelectric properties of new quaternary Heusler material: A first principles approach

Like full or half-heusler materials, equiatomic quaternary Heuslers (EQH) also display various intriguing physical properties. We carried out the strict and rigorous density functional theory calculations to estimate the stability of novel ferrimagnetic FeMnTaAl alloy. In this work, we considered the thermodynamic, energetic, dynamic and mechanical stability criteria, by evaluating the formation energy, phonon dispersion and elastic constants, respectively, which thereby suggest that the synthesis of FeMnTaAl as bulk phase is likely. Later, the electronic structure, magnetic and transport properties are determined from the ground state parameters. After the structural optimizations, the half-metallic character from spin resolved band structures and local spin moments (1 mu B) potentially felicitate its spintronic applications. Conservative estimates of Seebeck coefficient (similar to 85 mu V/K at 900 K), lattice thermal conductivity (2.8 W/mK at 300 K) and figure of merit (0.03 at 900 K) have also been put forward in this report. The overall structural stability, ferrimagnetism with large T c accompanied by transport properties will possibly enact the experimental realization for magnetic, thermoelectric or spintronic impressions of this material in future.