An investigation of half-metallic variant perovskites A2NbCl6 (A= K, Rb) for spintronic based applications

Abstract

Here we report an investigation of variant perovskite materials A2NbCl6 (A ​= ​K, Rb) for possible spintronic applications. This work includes the structural parameters, band structures, density of states, magnetic moments and Curie temperatures, which were derived from spin polarized density functional theory. The results establish the cubic structure stability of the present compounds in the ferromagnetic phase. The density of states confirmed a 100% spin polarizibility at the Fermi level. The responsible states for this polarizibility were identified as the d-states of the Nb atom. Electronically, the compounds were found to be metallic for the spin up channel but are direct band gap semiconductors for the spin down states. For both compounds the magnetic moment is calculated as 1 μb associated with the Nb atom. The Curie temperatures of K2NbCl6 and Rb2NbCl6 were computed by the random phase approximation (mean field approximation) to be 358.9 (538.4) K and 492.4 (738.6) K, respectively. The low magnetic moments and high Curie temperatures make these two compounds promising candidates for spintronic based devices.