HIGH-TEMPERATURE SUPERCONDUCTIVITY IN 123 AND OTHER CUPRATE PHASES OBTAINED IN AN EFFORT TO INVESTIGATE INTERGROWTH STRUCTURES

In an effort to synthesize copper oxides involving intergrowth structures, we have found several compositions giving rise to high-temperature superconductivity, most of them containing the 123-type phase. A novel 123 superconducting phase is found in the Y-Sr-Cu-O system. More interestingly, an oxide of the Y-Ba-La-Cu-O system showed zero resistivity around 210K. Existence of extra Cu-O layers in some of the intergrowth structures may also lead to high-Tc superconductivity.