Study of half-metallic behavior in Sr 2CoWO 6 perovskite by ab initio DFT calculations

Abstract

In this work, we report several ab initio calculations performed for Sr 2CoWO 6 by means of the density functional theory and the linearized augmented plane wave method for both spin orientations. For calculations, the exchange and correlation potential were treated into the generalized gradient approximation, which permits to consider from the beginning the difference between the electronic densities for both up and down spin orientations. The densities of states are calculated by the histogram method and the positions of Fermi levels are found by integrating over the density of states for both spin configurations. Our results reveal that Sr 2CoWO 6 material behaves as insulators for the spin-up orientation and conductor for the spin down, as expected for the half-metallic systems. Results of partial densities of states permit to conclude that the conduction band has predominant contributions of d x 2 - y 2 and d xz + yz states of Co for the spin-down orientation. A magnetic moment of 3 μ B was calculated. From the Murnaghan equation state, we also calculate the cell dimensions that minimize the total energy for several configurations.