| 摘要 |
PURPOSE:To improve the superconductive characteristic at the liquid nitrogene temperature (77K) by calcining a raw material mixed so as to become a Bi- series oxide having superconductivity, crushing it to a pasty condition, placing between silver plates, further heat-treating, and thereafter performing compressing working, and heat-treating again. CONSTITUTION:Five kinds of raw material powder, Bi2O3, PbO, SrCO3, CaCO3 and CuO are mixed by weighing so as to be Bi:Pb:Sr:Ca:Cu=0.97:0.24:1:1.5:1.6 by atomic weight ratio, and after that the mixed power is moved into an alumina dish and calcined. After the calcination, the calcined powder is crushed, mixed, added with terpineol so as to be paste condition, and a Bi series oxide layer is formed by screen-printing the paste on a silver board. After drying this Bi-series oxide phase together with the silver board, a silver layer foil is pressed on the Bi series phase and such material is produced layer that a Bi series oxide layer is sandwiched with silver plates. The material is compressed and performed compressing working in the temperature between 600 - 800 deg.C and after that again heat-treated in the temperature between 830 - 850 deg.C. |
