Electrical properties of interfaces in high-T$_{c}$ superconducting heterostructures

Electrical contacts between materials of different functionality are often required, both for technological applications as well as for fundamental research. However, contacts between different complex oxides frequently do not behave like expected. For example, it is well known that tunnel junctions are difficult to fabricate from high-T$_{c}$ superconductors, due to the presence of a degraded, non-superconducting layer underneath the tunnel barrier. We investigated the interface properties of a number of different oxide heterostructures, prepared by pulsed laser deposition. Specifically, the causes of non-ideal interface behavior, such as changes in the stoichiometry, oxygen deficiency, structural changes and electronic reconstruction, were investigated.