Ferrimagnetic half Heusler alloys for waste heat recovery application - First principle study using different exchange–correlation functionals.

ZrMnSi and HfMnSi half Heusler alloys with magnetic ground state are investigated through density functional theory. The different exchange–correlation functionals (GGA, LDA, PBESol and WC) are used to study these alloys. The equilibrium lattice constants and corresponding ground state energies are calculated using these four approximation methods. From GGA functional, the obtained band gap for ZrMnSi is 1.268 eV and HfMnSi is 1.311 eV. The reported alloys are predicted to be half metals from different potentials, where those alloys show semiconductor character in minority spin channel and also exhibit metallic character in majority spin channel. The studied alloys are mechanically stable and ductile in nature. The total magnetic moment of −3 μ B is obtained in the reported ferrimagnetic alloys. The obtained thermoelectric figure of merit for ZrMnSi and HfMnSi is 0.46 at 1200 K and 0.31 at 1200 K respectively, it shows that these alloys are the potential candidates for waste heat recovery application, and they are also useful for spin flip device application. • We studied the spintronic and thermoelectric properties of the ZrMnSi and HfMnSi. • We predicted the semiconductor character of the Heusler alloys ZrMnSi and HfMnSi. • For both of the Heusler alloys ZrMnSi and HfMnSi the band gap value is 1.29 eV. • The ZT is 0.46 and 0.31 for ZrMnSi and HfMnSi at 1200 K. • ZrMnSi and HfMnSi are best suit for spintronic and thermoelectric applications. [ABSTRACT FROM AUTHOR]