Investigating structure, magneto-electronic, elastic and thermoelectric properties of alkaline earth actinide perovskite oxide (BaBkO3) from first principle calculations

Abstract

First principle calculations with highly precise spin-polarized density functional theory (DFT) have been performed to study the structural stability, mechanical and magneto-electronic properties of cubic perovskite BaBkO3. The properties were studied under the generalized gradient approximation (GGA) and onset Coulomb interaction by WEIN2k package. The DFT and analytically calculated values of Goldschmidt tolerance (GT) factor in addition to stable-phase optimization show stability of the present material in the ferromagnetic cubic phase with a higher magnetic moment of 7 μB. This is because the nature of magnetism of 5f actinide materials (l=3) is governed by the large spin-orbit interaction and the hybridization of 5f electron orbitals with other states. The value of exchange and correlation potential were treated with different approximations: GGA and GGA + U calculations. Contribution of electronic states was studied through total and partial density of states using GGA and GGA + U approach. GGA + U calculations reveal an indirect band gap of 3.15 eV for BaBkO3 in the spin down channel supporting the half metallic nature and spin-polarized electronic band structure encourages complete spin polarization of the material with metallic character in spin up state. Mechanical properties like stability, stiffness, hardness, brittleness and ductility were discussed on the basis of elastic parameters obtained. The oxide perovskite BaBkO3 exhibit higher value of Seebeck coefficient and power factor at room temperature with a value of 150 μVK−1 and 5.1×1012 μWcm−1K−2s−1respectively. The properties of half-metallicity and higher Seebeck coefficient makes this material a promising candidate for thermoelectric and spintronic device applications.