Superconducting composite

A process for producing a superconducting composite comprising a superconducting sintered mass composed of perovskite or quasi-perovskite oxide represented by one of the following general formula (I) or (II):

• Y.sub.a Ba.sub.1-a Cu.sub.y O.sub.z (I)
• La.sub.a Sr.sub.1-a Cu.sub.y O.sub.z (II)
• wherein a is 0.4-0.6 and y is 0.5-1 in Formula I and a is 0.4 and y is 1 in Formula II, and "z" represents a number which is selected from a range of from 1 to 5, and
• a metal phase dispersed in said superconducting mass with a proportion of from 10 to 70 volume % in the composite, the metal of the metal phase possessing higher heat-conductivity and higher specific heat than the surrounding sintered mass;
• said process comprising the steps of:
• preparing a powder mixture comprising a powder of oxide or carbonate of Sr or Ba, a powder of oxide or carbonate of La or Y and a powder of oxide or carbonate of Cu in such proportions that the atom ratio of said elements "Sr or Ba":"La or Y":Cu is adjusted to that defined in Formulae I and II,
• subjecting the powder mixture to preliminary sintering,
• pulverizing a preliminary sintered mass,
• admixing metal powder with the resulting pulverized powder,
• compacting the resulting metal-containing powder mixture into a shaped body, and
• subjecting the shaped body to the final sintering to producing a superconducting composite comprising a metal phase dispersed in a superconducting material.