Electrical Instability in CuO1-x: Possible Correlations with the CuO-based High Temperature Superconductors

Physical properties of stoichiometric and non stoichiometric CuO are reported. The electrical conductivity has been measured on CuO pellets, sintered with the usual procedure for the preparation of Y Ba-Cu O superconductors and then deoxygenated under a nitrogen flow. It is shown that oxygen deficient CuO pellets present abrupt and large resistivity drops as the temperature decreases below 230-200 K. Possible correlations between the electrical instability of oxygen deficient CuO and the high temperature superconductivity problem are discussed