Melt-textured YBa2Cu3O7 for low-field applications in microwave devices

摘要

We report the results of an investigation of microwave power loss at 10 GHz in YBCO at 77 K. The samples are melt-textured YBa2Cu3O7 (123) with 28 mole % Y2BaCuO5 (211) inclusions and x% of Ag added to bridge the gaps at the grain boundaries. The sample with 10% Ag shows critical currents >108 amp/m2 at 77 K. Measurements down to 77 K show that microwave power loss drops more sharply (through Tc of 89 K) with higher Ag content. DC magnetic-field-induced microwave absorption (MWMA) recorded at 77 K shows that in these samples the low (～10 mT) field loss is drastically reduced with respect to that in typical YBCO ceramics.