High Jc YBCO superconductors prepared by the powder melting process

This paper reports on the development of a method named powders melting process (PMP) to prepare high Jc YBCO superconductors. The YBCO conductors have been fabricated through continuous zone melting and unidirectional solidification process using precursor powders of Y{sub 2}BaCuO{sub 5} (211) phase and Ba-Cu-O as starting material. The transport Jc values of the samples measured by standard continuous d.c. four-probe method exceed 20000 A/cm{sup 2} at 77K, 1T, and 12000 A/cm{sup 2} at 77K, 4T. The microstructure investigations indicate that the 123 grains are well oriented, fine and dispersive 211 particles remained in the samples. The YBCO conductor with various dimensions 0.2-5 {times} 0.2-5 {times} 30-100 mm{sup 3} can be fabricated by the PMP method. This new approach will be potentially beneficial for fabricating oxide conductors with metal substrates since its melting temperature is lower than that of other melt process by about 100{degrees}C.