HIGH PRESSURE SYNTHESIS AND SUPERCONDUCTIVITY OF Sr2CuO2+δCl2-y BY APICAL OXYGEN DOPING

Using the apical oxygen doping mechanism, i.e. a partial substitution of divalence O for the monovalence Cl, a p-type copper oxychloride superconductor, Sr2CuO2+δCl2-y, was synthesized at 1050°C under 6.0 GPa for 1h. The X-ray powder diffractions show that the main phase has a tetragonal structure with a=3.93A, c=15.65 A. The magnetic susceptibility as well as resistance measurements indicated that the bulk superconducting transition temperature of the sample is 30K.