Joining of Two YBCO grains by multi-seeding techniue

Korea Atomic Energy Research Institute

@Chan-Joong Kim and Ho-Jin Lee

　 We studied top-seeded melt growth process (TSMG) as a joining method for YBCO superconductors. Two SmBCO seed crystals were placed on a YBCO compact prior to TSMG process and the TSMG process was followed for the compact. The two YBCO grains were connected by the peritectic growth of the Y123 grains in the mixture of solid and liquid. Sometimes, residual liquid was observed at the grain junction, which decreased the magnetic leviation force and trapped magnetic properties in the regions containing the grain juction. Adjustment of the starting composition toward the Ba-excess regime and the control of the melt wetting angle are the ways to minimize the degradation of the properties at the grain junctions.