Abstract
Formation and stability of the transition metal-substituted cobaltites in alkaline solution were investigated with hydrothermal technique. Two kinds of cobaltites, Co3O4 and ZnCo2O4 were obtained throughout whole reaction temperature range and MnCo2O4 was obtained below 110°C or above 550°C. Between these temperatures MnCo2O4 dispropotionated to spinel and other compounds. FeCo2O4 was also unstable and disproportionated to Fe-poor cobaltite and Co-poor cobalte ferrite in alkaline solution. Other kinds of transition metal-substituted cobaltite were not obtained in these experimental conditions.
