Oxygen vacancy migration along dislocations in SrTiO3 studied by cathodoluminescence

Abstract

The impact of dislocations on oxygen vacancies in un-doped SrTiO3 single crystal has been investigated by cathodoluminescence (CL). The dominated luminescence peak located at ~2.8 eV is originated from oxygen vacancies. Enhanced luminescence has been observed at specific dislocations with the accumulation of oxygen vacancies. Under annealing either in oxidizing or reducing atmosphere, the diffusivity of oxygen ions at dislocation cores is nearly the same as that in the bulk. CL results suggest that the accumulation of oxygen vacancies is easily triggered by dislocations, while the diffusion of oxygen vacancies may not be significantly affected.