Ag doping effects on the microstructure and properties of unidirectional grown Y-Ba-Cu-O superconductors

The Ag doping effects on the unidirectional solidification of YBCO superconductors have been studied. The unidirectional solidification was realized by the zone melting process using an infrared radiation convergence furnace. The continuous crystals were obtained by the process. Ag distributed independently in the intergrain and grain boundary at nearly the same size. Increasing the Ag content, the a-b plane of the 123 superconducting phase aligned to the solidified direction and the (110) textured sample has been obtained by the addition of the 20 wt.%. By the addition of Ag, the I/sub c/ characteristics were improved drastically and the obtained sample (approximately 4 mm in diameter) shows a high critical current value of over 2000 A.<>