The annealing behaviour of oxygen vacancies introduced by epitaxial growth of DyScO3 or SrTiO3 films on SrTiO3 substrates was studied by positron annihilation. Many oxygen vacancies (VO) were introduced near the interface in SrTiO3 substrates when 10nm DyScO3 or 20nm SrTiO3 films were grown by pulsed laser deposition at 10−2 Torr or 10−6 Torr oxygen pressure, respectively. Post-annealing in oxygen ambient could partly compensate those vacancies in the SrTiO3/SrTiO3 samples while no vacancy compensation was observed in the SrTiO3/DyScO3 or SrTiO3/DyScO3/SrTiO3 heterostructures. This suggested that epitaxial DyScO3 films could be used as passivation layers to suppress the diffusion of oxygen vacancies.

Epitaxial DyScO3 Films as Passivation Layers Suppress the Diffusion of Oxygen Vacancies in SrTiO3. G.Yuan, K.Nishio, M.Lippmaa, A.Uedono: Journal of Physics D, 2010, 43[2], 025301