Mechanism of the decomposition of cobaltous compounds in vacuo

The decomposition of cobaltous compounds (nitrate, hydroxide, carbonate, oxalate and oxyhydroxide) in vacuo has been investigated by magnetic methods and thermogravimetry. The mechanism is shown to be similar to that in air and begins with the formation of Co³⁺ ions in octahedral coordination. The formation of different final products (Co₃O₄, CoO and Co) has been attributed to the nature of the initial cobaltous compound. The results are in agreement with thermodynamic calculations.