Ab initio study of the magnetic, optical and electronic properties of spinel Co3O4 within DFT and GW approaches

Ab initio study of the magnetic, optical and electronic properties of spinel Co3O4 within DFT and GW approaches Автор:: Zhandun, Vyacheslav S.; Nemtsev, Andrey JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS . DOI: 10.1016/j.jmmm.2019.166306

The spinel cobalt oxide Co3O4 is an antiferromagnetic semiconductor containing two non-equivalent Co2+ and Co3+ cobalt ions with different local environments and different magnetic moments. We have performed ab initio study and comparison of the electronic, magnetic and optical properties of Co(3)O(4 )within GGA, GGA + U, and G0W0 approximations. GGA correctly predicts Co3O4 to be a semiconductor, but severely underestimates the bandgap. G0W0 approximations increase the bandgap indicating a better description of the cobalt localized d-states. The spectral weights of the bands near Fermi energy are about 0.5. Ab initio calculations confirm that the low-spin state of Co3+ ion arises due to the local environment and the crystal effect field. The investigation of the pressure dependencies of magnetic properties revealed the appearance of Co3+ ion abrupt transition from low-spin state to high-spin state under tensile pressure. This allows manipulating the spin state of Co(3+ )ions through the pressure or strain.