SUPERCONDUCTIVITY OF LA2-XSRXCUO4 WITH HIGH STRONTIUM CONCENTRATION BY SULFUR DOPING

The effects of sulphur substitution for oxygen on the structure and pr operties of non-superconducting La2-xSrxCuO4, where x = 0.26 and 0.30, have been studied. In La2-xSrx-CuO4-ySy, the sulphur-doped samples ex hibit superconducting transition at 37-39 K and a larger Meissner effe ct than undoped samples. It was found that the superconductivity of La 2-xSrxCuO4-yS, is apparently determined by the value of x-y and the st rontium concentration region in which La2-xSrxCuO4 shows superconducti vity shifts to higher strontium concentrations with sulphur doping.