Mechanical persistent current switch made of RE-Ba-Cu-O bulk with resin impregnation

We studied the possibility to construct a mechanical persistent current switch using a pair of bulk YBCO superconductors with resin-impregnation. Supercurrents could not be passed between two YBCO bulks when the currents were passed along the c-axis. In contrast, supercurrents as large as 13.5 A could be successfully passed between two YBCO cubes 8 mm in side length at the compression force of 500 N when the currents were passed along the ab-axis. The contact surfaces were observed by scanning electron microscopy after the transport measurements at 500 N load. The damage was observed on the (0 0 1) contact surface, while no damage was present on the (1 0 0) surface, reflecting superior contact characteristics.