Preparation of superconducting thin films of (La1−xSrx)yCuO4−δ by sputtering

Abstract
Superconducting thin films of (La1−xSrx)yCuO4−δ have been prepared by sputtering with careful control of such preparation parameters as target composition, total pressure and composition of gases in the reactor, substrate material and temperature, and annealing conditions. In accordance with the bulk target materials, the superconducting films show K2NiF4‐type x‐ray diffraction patterns, although this crystal structure was not the sole requisite for the superconductivity of the films. The films prepared thus far have a superconducting transition onset of about 36 K and turn out to be fully superconducting at temperatures below 10 K.