SUPERCONDUCTIVITY AND HOLE CONCENTRATION OF LA3-XCA2XBA3-XCU6OY COMPOUNDS

The relationship between superconductivity and hole concentration was studied in a series of tetragonal triple-perovskite La3-xCa2xBa3-xCu6O y (0 less than or equal to x less than or equal to 1.00) compounds. It was found that its superconductivity was dependent on the hole concen tration of the Cu-O layers, but not on the hole concentration of the c ompound. It was semi-empirically demonstrated that superconductivity o ccurred in the Cu-O layers but not in thr Cu-O chains in the La3-xCa2x Ba3-xCu6Oy compounds. Moreover, this explained the reason why La3Ba3Cu 6Oy was not superconducting in terms of the degree of its hole concent ration.