The Origin For Increase Of Magnetic Moment Of Co In Co-Doped Sno2 With Oxygen Vacancies

In Co-doped SnO(2) fivefold degenerate Co-3d states split into five singlet states. The magnetic moment of Co is mainly contributed by the spin polarization of Co-d(xy) states. The introduction of oxygen vacancies largely increases the magnetic moment of Co. The increase of Co magnetic moment is caused by the conversion of spin-spin coupling between Co and its neighboring O atoms from antiparallel to parallel, which attributes to the hybridization and electrons transfer between oxygen vacancy impurity states and Co-3d states.