Textured superconductors: progress in processing and development of applications

The present review stresses the potentiaHty of directional soHdification techniques for the preparation of bulk YBa2Cu307/Y2BaCu05 composites with high critical currents useful for several applications .We analyse the growth mechanisms and we show how the size of 211 precipitates can be refined .We also present detailed TEM investigations of the defect formation mechanisms and a complete investigation of the influence of 211 phase concentration on the critical currents . The pinning mechanisms have been identified from the field (up to 20 T) and temperature dependence of the critical currents . This allow us to propose the first complete magnetic phase diagram of these type II superconducting materials . Finally , we stress the potential of these melt textured ceramics in several technological applications such as current leads, fault current limiters, flywheel batteries and hysteresis motors.