Interface Microstructure and Composition of a YBa2CU3O(7-x) /N/ YBa2Cu3O(7-x) SNSEdge Junction with CaRuO3 as the Metallic Barrier

摘要

Superconductor- normal-superconductor (SNS) edge junctions consisting ofYBa2Cu3O7/CaRuO3/YBa2Cu3O7 were fabricated on (001) LaAlO3 substrates using laser deposition. These devices display an excess resistance which may be related to the SN interface and normal layer structure or composition. High-resolution and conventional transmission electron microscopy were employed to investigate the SN interface structure to determine the degree of interface-matching and possible interfacial defects. Energy-loss spectroscopy and energy dispersive x-ray analysis were performed on the CaRuO3 film and near interface regions to determine the normal layer composition and to quantify the extent of interdiffusion between the CaRuO3 and YBCO films. Results are compared to recent investigations of SNS edge junctions consisting of YBa2Cu3O(7-x)/ YBa2Cu(2.79)Co(0.21) O(7-x)/YBa2Cu3O(7-x). jg.