| 摘要 |
PURPOSE:To obtain a Bi-based oxide superconductor of 2,212 phase showing a higher critical temperature than 90 deg.K without passing through a quenching process by blending Bi with Sr, Ca, Na, Ba and Cu in a specific ratio, calcining, grinding, molding and burning in a nitrogen atmosphere. CONSTITUTION:Raw materials containing Bi, Sr, Ca, Na, Ba and Cu are mixed so as to give an atomic ratio of 1.0 Bi, 0.6-1.2 Sr, 0.35-0.7 Ca, 0.05-0.2 Na, 0.05-0.2 Ba and 1.0+ or -0.2 Cu, calcined at 790-870 deg.C, ground, molded and burnt in a nitrogen atmosphere or a nitrogen atmosphere containing <10vol.% oxygen at 780-950 deg.C for 20-100 hours to give a Bi-based oxide superconductor shown by the formula (A is 0.6-1.2; B is 0.35-0.7; C is 0.05-0.2; D is 0.05-0.2; figure shows atomic ratio). |
