High Temperature and High Pressure Synthesis and Study of 0212-Type Ca3Cu2O4+Cl2-y

Using the apical oxygen doping mechanism, i. e. a partial substitution of divalence O for the monovalence Cl, we synthesized Ca3Cu2O4+Cl2-y with Ag2O under high temperature and high pressure. From X-ray diffraction composition analysis, we confirmed that Ca3Cu2O4+Cl2-y crystallizes into a 0212 structure. With increasing the content of Ag2O, we found that lattice parameters a shrinked but c increased. It suggested that it should be hole doping. We also investigated the temperature dependence of the electrical resistivity and DC magnetic susceptibility for two samples, but we didn't observe superconductivity. It maybe resulted from the too low density of hole carrier.