Preparation and characterization of the superconductor [Y0.8Ca0.2]SrBaCu2.8(BO3)0.2O6.4 compound

We report the study of the [Y0.8Ca0.2]SrBaCu2.80(BO3)0.2O6.4 compound which is a superconductor with critical temperature of 45 K. This compound was prepared by the solid state reaction method under normal conditions of pressure and temperature, replacing 0.2 of oxianion borate (BO3)3- in the copper site of [Y0.8Ca0.2]SrBaCu3O7-δ. TC was determined by measuring the magnetic susceptibility using a SQUID detection system. The X-ray difractogram revealed a monophasic pattern, Rietveld analysis suggested an orthorhombic crystalline structure belonging to the Pmmm spatial group with a=3.826 Angst, b=3.861 Angst and c=11.561 Angst