Electrical properties of electron and ion beam irradiated YBa2Cu3O7-δ

An electron beam with sufficient energy can be used to create a high quality Josephson junction in a single laver of YBa2Cu3O7-delta. The number of junctions thus produced is severely limited by the serial nature of the technique. An alternative method to create similar high quality Josephson junctions without such a serious throughput limitation is possibly the combination of high resolution masking and ion irradiation. Far this reason we have studied the electrical properties of both electron and proton irradiated YBa2Cu3O7-delta in some detail. It was found that the resistivity of electron beam irradiated barriers of intermediate length (200 nm) are strongly influenced by a proximity effect when the irradiated material has a finite T-c. At higher electron doses the superconducting properties are fully suppressed and the electrical behaviour is dominated by a Variable Range Hopping mechanism.