CONDUCTIVITY MEASUREMENTS ON COBALT AND NICKEL OXIDES IN HIGHLY-ENRICHED OXYGEN ATMOSPHERES

The pressure dependencies of the conductivities of nickel and cobalt monoxides have been investigated in the range 10-2 to 7.5 × 102 atmospheres at temperatures in the region of 1000° C. Conductivity saturation occurs in CoO due to the formation of Co3O4, and the experimental data correlates well with a model for the separation of the higher phase. NiO exhibits no saturation effect in the pressure range investigated and the p1/5 dependence of the conductivity at 950° C with this oxide above 0.1 atm is interpreted in terms of the formation of singly ionised vacancies. © 1969 Chapman and Hall.