High-temperature superconductor

A superconductor of the Bi--Sr--(Ca)--CuO.sub.2 system comprising:

• (Bi.sub.1-u Pb.sub.u).sub.2 (Sr.sub.1-x-y Ca.sub.x Bi.sub.y).sub.4 Cu.sub.3 O.sub.10+d
• wherein 0.01<x<0.5
• 0.ltoreq.y<x<0.5
• 0.ltoreq.d
• 0.ltoreq.u,
• said superconductor having a layer structure formed by the oxides including bismuth, lead, strontium, calcium, and copper wherein the layer sequence of the oxides is as follows:
• at least one compound chosen from the group consisting of bismuth and lead;
• at least one compound chosen from the group consisting of strontium and calcium;
• copper;
• at least one compound chosen from the group consisting of calcium and strontium;
• copper;
• at least one compound chosen from the group consisting of calcium and strontium;
• copper;
• at least one compound chosen from the group consisting of strontium and calcium;
• and at least one compound chosen from the group consisting of bismuth and lead, said superconductor having a transition temperature greater than 90 K.

A method of manufacturing a superconductor of the Bi--Sr--(Ca)--Cu--O2.sub.x) system including (Bi.sub.1-u Pb.sub.u).sub.2 (Sr.sub.1-x-y Ca.sub.x Bi.sub.y (.sub.4 CU.sub.3 O.sub.10+d wherein 0.1<x <0.5

• 0<y<x<0.5
• 0<d
• 0<u,
• having a transition temperature greater than 90 K., said superconductor consisting of unit cells, each unit cell including a structure having first and second alternating layers, said first alternating layer including a double layer of at least one of Bi-oxide and Bi/PB oxide, said second alternating layer including perovskite cells having alternating layers of Cu-oxide and at least one of Sr-oxide and Ca-oxide, said structure including three Cu-oxide layers between two double layers, comprising the steps of:
• converting a material having a weighted-in quantity Bi.sub.1.7 Pb.sub.0.4 Sr.sub.1.7 Ca.sub.2.1 Cu.sub.3 at 800.degree. C. for three hours to produce a first resultant material;
• converting said first resultant material at 820.degree. C. for 10 to 20 hours in air with an immediate grinding to produce a second resulting material;
• grinding and processing said second resultant material to produce a third resuitant material;
• and
• sintering said third resultant material at approximately 843.degree. C. for 60 through 120 hours in an argon-oxygen mixture having P.sub.0 =1/13 bar.

A method of manufacturing a superconductor comprising the steps of:

• converting a material having a weighted-in quantity Bi.sub.1.7 Pb.sub.0.4 Sr.sub.1.7 Ca.sub.2,1 Cu.sub.3 800.degree. C. for three hours to produce a first resultant material;
• converting said first resultant material at 820.degree. C. for 10 to 20 hours in air with immediate grinding to produce a second resultant material;
• grinding and processing said second resultant material to produce a third resultant material;
• and
• sintering said third resultant material at 860.degree. C. to 865.degree. C. for 60 through 120 hours in air.

A superconductor of the Bi--Sr--(Ca)--CuO.sub.x system comprising:

• (Bi.sub.1-u Pb.sub.u).sub.2 (Sr.sub.1-x-y Ca.sub.x Bi.sub.y).sub.4 Cu.sub.3 O.sub.10+d
• wherein 0.01<x<0.5
• 0.ltoreq.y<x<0.5
• 0.ltoreq.d
• 0.ltoreq.u, having a transition temperature greater than 90 K., said superconductor consisting of unit cells of a sintered structure, each unit cell including a structure having first and second alternating layers, said first alternating layer including a double layer of at least one of Bi oxide and Bi/Pb-oxide, said second alternating layer including perovskite cells having alternating layers of Cu oxide and at least one of Sr-oxide and Ca-oxide, and said superconductor having three Cu-oxide layers per half unit cell.