First principle prediction of vacancy-induced magnetism in non-magnetic perovskite SrTiO3

A theoretical study of magnetization in non-magnetic cubic perovskite SrTiO3 induced by vacancies in Sr, Ti and oxygen sublattices is presented using the full-potential linear augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA) for the exchange-correlation potential. The results show that the oxygen and titanium vacancies lead to the magnetization of non-magnetic perovskite SrTiO3 due to the spin-polarization of valence states for the Ti and O atoms, nearest to these vacancies. In result the insulating SrTiO3 becomes metallic-like with magnetic moments (per cell) 1.30 μB and 3.54 μB for non-stoichiometric SrTiO3−δSrTiO3−δ and SrTi1−δOSrTi1−δO, respectively. On the contrary, our calculations reveal that for Sr vacancy the non-magnetic state of perovskite is retained, whereas the electronic spectrum of Sr1−δTiO3Sr1−δTiO3 also adopts metallic-like type.