Abstract

There is renewed interest in the properties of hetero- and homophase boundaries in the perovskite oxide SrTiO3 because of this material’s possible application in all-oxide electronics, as a high-k dielectric, and in resistive-switching devices. In this talk I focus on the interplay between point defects and interfaces (grain boundaries and surfaces) in acceptor-doped SrTiO3. Experimental results obtained for various symmetrical low-angle [001] tilt grain boundaries are presented. The results are examined within a thermodynamic framework that allows the properties of grain boundaries in acceptor-doped SrTiO3 to be predicted. The aim is to derive relationships between the crystallographic structure of an interface and its transport properties. The second part of the talk concerns non-uniform defect distributions at the (100) surface of SrTiO3. A method for probing such non-uniform defect distributions will be presented, together with experimental data obtained for single crystal substrates. The origins of the non-uniform defect distributions will also be discussed. Lastly, the implications of results for SrTiO3-based oxide heterostructures are examined.