| 摘要 |
PURPOSE:To improve superconductive characteristic by making arrangement of oxide and silver appropriate and increasing the boundary face area between both. CONSTITUTION:A multiple tube is made by arranging silver tubes 2, 3 coaxially around a silver core 1, and is annealed at a fixed temperature for fixed time, and thereafter calcined powder being filled in vacant space 4, a copper cap 6 having the opening 5 in the center is attached. Being worked for grooved roll wire drawing, this multiple tube is cold-worked into tape shape by way of plane roll work, and further is annealed. In this way, melting Bi oxide partially so as to form crystal, the crystal grows in one direction on a gradual cooling process. Therefore, the left silver exhibits catalytic effect, the melting point of oxide is lowered, the reaction is hastened, and further composition of grown liquid phase and deposited superconductive phase is homogenized. Thereby quantity of non-superconducting phase is reduced and high orientation of crystal is realized. Excellent critical temperature and critical current density is obtained as the result. |
