Electronic, Structural and Magnetic Properties of the Sr 2 CoWO 6 Double Perovskite Using GGA (+ U)

Abstract

Physical properties of the Sr2CoWO6 (SCWO) double perovskite are studied within the framework of density functional theory (DFT) using the generalized gradient approximation (GGA) and strong correlation correction (Hubbard approach or GGA+U). For adjusting the Hubbard parameter, after full structural optimization (relaxation of both lattice parameters and ionic positions), the band gap is calculated using density of states (DOS) and compared with others results. Then, by optimized U, the structural, electronic, and magnetic properties of this compound are investigated in paramagnetic (PM), ferromagnetic (FM), and anti-ferromagnetic (AFM) phases by employing GGA and GGA+U approaches. The results of GGA+U are in more agreement with the available experimental and theoretical results, compared to the ordinary GGA. The GGA+U calculations predict that ground state of the SCWO is anti-ferromagnetic half-metal (HM) and presence of the cobalt atoms cause both half-metallic and magnetic behaviors. The band structure shows an indirect gap about 1.7 eV in spin up direction.