Fabrication of Superconducting Y-Ba-Cu Oxide Through an Improved Diffusion Process

Abstract
The formation of the YBa2Cu3O7-y layer has been investigated by a modified diffusion process as a basic research for high-T c superconductor fabrication. The starting materials were Y2BaCuO5 and barium cuprate (Ba:Cu=3:5), unlike the ordinary sintering technique. A dense layer of YBa2Cu3O7-y was formed on Y2BaCuO5 substrate, and the starting barium cuprate layer was fully converted to the superconducting phase. X-ray diffractometry revealed that the layer consisted of an orthorhombic crystal structure. A zero resistance of 91.5 K and a critical current density of 1900 A/cm2 (77 K, 0 T) were achieved in the layer.