Enhancement of the trapped-fields and mechanical properties of Nd–Ba–Cu–O bulk superconductors

We have studied the effects of processing conditions and the initial compositions in Nd–Ba–Cu–O bulk superconductors on the field-trapping capability and the mechanical properties. Sintering the sample prior to the crystal growth was effective for the fabrication of a good quality sample with high trapped-fields. The optimization of Nd422 and Ag contents along with processing conditions led to an increase in both the field-trapping ability and mechanical properties. As a result, the trapped-field of Nd–Ba–Cu–O 30 mm in diameter reached 1.4 T at liquid nitrogen temperature. The average tensile strength and the Weibull coefficient exceeded 50 MPa and 13, respectively.