Characteristics of Advanced YBa sub 2 Cu sub 3 O sub x /PrBa sub 2 Cu sub 3 O sub x /YBa sub 2 Cu sub 3 O sub x Edge Type Junctions

The scaling behavior and Josephson properties of improved YBCO /PBCO/YBCO edge-type junctions are described. The critical current, normal-state resistance, and I sub c R sub n product scale with barrier thickness and junction area. The coherence length of the PBCO barrier is estimated to be 5-8 nm. As unambiguous evidence of the Josephson behavior, the microwave response as a function of microwave power, and the current modulation with applied magnetic field have been studied: well-developed Shapiro steps at 10 GHz have been observed, and the modulation of I sub c (H) shows Fraunhofer-like behavior with 95% I sub c suppression.