Patent ID: 7135438

Claim:
A method of producing a substantially single phase superconducting material of chemical composition M 2 M′Cu 3 O y having T c (R=0) of 82 K or above, with M being Ba and M′ being selected from Y, Y and La, and Y and Sc, the method comprising the steps of: a) mixing stoichiometric quantities of particles of copper oxide, one or more of Y oxide, Sc oxide and La hydroxide, and a Ba-compound selected from Ba oxide and Ba carbonate, such that an intimate mixture results; b) calcining said intimate mixture at a predetermined temperature in the approximate range 700–950° C. in an oxygen-containing environment for a time sufficient to result in calcination of substantially the entire mixture; c) pulverizing the calcined material of step b); d) forming said pulverized calcined material into a shape; e) sintering said shape in an oxygen-containing environment at a temperature of about 950° C. for a time sufficient for substantial densification to occur; and f) cooling said sintered shape in an oxygen-containing environment at a rate selected to yield said substantially single phase superconducting material having T c (R=0) of 82 K or above.