First-Principles Study of Structural, Elastic, Mechanical, Magnetic, Electronic and Thermoelectric Properties of Half Metallic Ga2NbX6 (X = Cl, Br) Variant Perovskites

We present the study of half metallic variant perovskites Ga2NbX6 (X = Cl, Br) using the scheme of the density functional theory. Various features such as, structural, elastic, mechanical electronic, magnetic and thermoelectric properties were calculated through full-potential linearized augmented plane wave method in the computer simulation package of Wien2k. Both the perovskites were found to be stable from values of formation energy, tolerance factor and positive frequencies of phonons. In addition, the mechanical stability was confirmed from elastic constants. The mechanical properties confirmed ductile nature of both variant perovskites. The electronic properties showed that these compounds were metallic in spin up state and semiconductor in spin down state. The magnetic moments were calculated as 1 mu (B) for both the compounds majorly associated with the Nb atom. The 100% spin polarizibility favors the use of Ga2NbX6 variant perovskites for spintronic based applications. Moreover, the calculated spin dependent thermoelectric properties favored both perovskites for the spin Seebeck effect.