INTERFACE MICROSTRUCTURE AND COMPOSITION OF A YBA2CU3O7-X N/YBA2CU3O7-X SNS EDGE JUNCTION WITH CARUO3 AS THE METALLIC BARRIER/

Superconductor-normal-superconductor (SNS) edge junctions consisting o f YBa2Cu3O7/CaRuO3/YBa2Cu3O7 were fabricated on (001) LaAlO3 substrate s using laser deposition. These devices display an excess resistance w hich may be related to the SN interface and normal layer structure or composition. High-resolution and conventional transmission electron mi croscopy were employed to investigate the SN interface structure to de termine the degree of interface matching and possible interfacial defe cts. Energy-loss spectroscopy and energy dispersive X-ray analysis wer e performed on the CaRuO3 film and near interface regions to determine the normal layer composition and to quantify the extent of interdiffu sion between the CaRuO3 and YBCO films. Results are compared to recent investigations of SNS edge junctions consisting of YBa2Cu3O7-x/YBa2Cu 2.79Co0.21O7-x/YBa2Cu3O7-x.