SUPERCONDUCTORS HAVING CONTINUOUS CERAMIC AND ELEMENTAL METAL MATRICES

摘要

Composite bulk superconducting materials having desirable physical, measured transport current density and high Tc superconducting characteristics are provided which comprise a first matrix of superconducting ceramic oxide crystalline grains with a second matrix of elemental metal (gold, silver, palladium and tin) situated within the interstices between the crystalline grains. Preferably, each matrix is a continuous phase within the composite material, with the ceramic oxide preferably being present at a level of at least about 80 % by weight, whereas the elemental metal is present at a level of up to about 20 % by weight. In fabrication procedures, a presursor superconducting ceramic oxide is first prepared and reduced to a fine powder size; this is mixed with powdered elemental metal, and the mixture is compressed using high compaction pressures of the order of 14 tons/cm<2> or greater to form a body, which is then sintered to yield the composite. Particularly preferred composites include a mixed metallic matrix including respective quantities of tin and a noble metal.