THE SYNTHESIS OF INFINITE-LAYER CaCuO₂ AND HYPOTHETICAL p-TYPE DOPING WITH Na UNDER HIGH-PRESSURE

The CaCuO₂ with infinite-layer structure (IL CaCuO₂) was synthesized under high-pressure. The p-type doped infinite layer compounds Ca_1-xNa_xCuO₂ with the different carriers concentration (x=0.05, 0.1) were also prepared from high temperature and high-pressure technique. The lattice parameter a decreases with increasing Na content x in the p-type doped Ca_1-xNa_xCuO₂, suggesting that the hole like carriers enter into the CuO₂ plane, and Na is successfully doped into the infinite-layer CaCuO₂. This was confirmed by the systematic evolution of resistance with increasing the doping level. However, no superconductivity was observed in the samples.