Abstract:
Incorporation of BO3-3 ion stabilizes YSr2Cu3O7, but the borate derivative is non superconducting. Superconductivity is not obtained by the partial substitution of Y by Ca in YSr2Cu3-x(BO3)xOz. Superconductivity has however been found in YSr2-yBay3Cu3-x(BO3)xOz as well as Y0.5Ca0.5Sr2-yBayCu3-x(BO3)xOz (y-1, x=0.25). The borate ion is coordinated to copper reducing its point group symmetry. Observation of superconductivity in borate derivatives prepared under ambient conditions is noteworthy.
