The epitaxial (001)-oriented 250nm BiFeO3/50nm SrRuO3 films were deposited on

DyScO3 and SrTiO3 substrates, respectively. Following the growth, the cooling in

lower oxygen pressure results in the creation of oxygen vacancies at the surface of

the BiFeO3 film and the epitaxial strain drives these vacancies to diffuse from the

film surface to the film interface. The SrTiO3 substrate strongly absorbs oxygen

vacancies from the BiFeO3 film while the DyScO3 substrate does not. Therefore, the depth distribution of oxygen vacancies depends on the oxygen pressure during

cooling, the epitaxial strain, and the substrate absorbing oxygen vacancies.

The Dependence of Oxygen Vacancy Distributions in BiFeO3 Films on Oxygen

Pressure and Substrate. G.L.Yuan, L.W.Martin, R.Ramesh, A.Uedono: Applied

Physics Letters, 2009, 95[1], 012904