The discovery of colossal magnetoresistance (CMR) 1 in thin film perovskite-like manganites has renewed interest in their possible use in device applications. 2 One of the crucial issues in thin film CMR manganites is the role of finite size effects related to structure on the thin film properties. Due to the restricted geometrical dimensionality of a thin film, a change in the layer thickness changes the metal-to-insulator transition temperature Tc. There exist several key areas for which we do not have a fundamental understanding of the physical processes that are occurring. Many of the problems arise from a poor understanding of the magnetism and structure at, or close to the interface region between the layer and the substrate.