Interface superconductivity – Possible origin of high critical temperature in layered superconductors

Superconducting transition temperatures Tc of the YBCO film interfaces were measured inductively. It was observed that the interface-Tc is always higher then the surface-Tc probably because of the substrate influence. Deposition of the silver over-layer on the film surface enhances also its critical temperature. In the annealed YBCO/Ag bilayers magnetic properties of the interface were observed. This two dimensional structure reminds the layered microstructure of the high-temperature superconductors and one can suppose that enhanced superconductivity of the interfaces is the origin of the high critical temperatures in layered superconductors.