OXIDE SUPERCONDUCTOR AND PRODUCTION THEREOF

摘要

PURPOSE:To enable omission of a long-hour heat treatment in an oxygen atmosphere after calcination in production of the subject oxide superconductor having a high superconductivity transition temperature by specifying its composition so that a rare earth element R and Ba of RBa2Cu3O7-x may be partly substituted respectively with Ca and Sr. CONSTITUTION:The objective oxide superconductor is represented by the formula [R is one or more rare earth element selected from Tm, Yb and Ly; 0.1<=x<=0.5; 0.1<=y<=0.4; 0.05<=z<=(x/2 + 0.5)]. This oxide superconductor can be produced by calcining a composition of (R1-xCax)(Ba1-ySry)2Cu3O7-x while controlling the oxygen partial pressure [P(O2)] to 0.001atm<=P(O2)<=0.2atm and subsequently adjusting the amount (z) of oxygen defect to a value within the above-mentioned range by heat treatment. The objective 1-2-3 type oxide superconductor having a relatively high superconductivity transition temperature can be produced at a low cost thereby without a long-hour heat treatment at 300-500 deg.C in an oxygen atmosphere.