Study of YBa2Cu3O7-delta ceramics/Al interface

Properties of oxide layers at the interface between Al metal and YBa2Cu3O7- delta ceramics were investigated using X-ray diffraction (XRD), X-ray photo electron spectra (XPS) and impedance measurements. There have been found th e oriented grains having their c-plane parallel to the surface of YBa2Cu3O7 -delta. When Al metal was evaporated onto the ceramics sample, the aluminum oxide layer was produced at the interface between Al and YBa2Cu3O7-delta b ecause Al metal oxidizes more easily. The oxygen-deficiency was observed at the ceramics side of the interface as examined by X-ray photoelectron spec tra. This oxygen-deficiency can be partly replenished by post annealing whe reas it can be fully replenished for the sample to which the mechanical pol ishing is applied beforehand in order to remove the oriented grains. The th ickness of aluminum oxide layer was evaluated by means of the impedance mea surements using the alternating current three-terminal method. (C) 2001 Pub lished by Elsevier Science B.V.