A strong anomaly was found in the heat capacity of Co3O4 between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co3O4 to CoO. The measured entropy of transition, ΔS=46±4 J mol-1 K-1 of Co3O4, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co3+ cations. Experimental values of heat capacity, heat content and entropy of Co3O4 in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53±4 kJ mol-1 of Co3O4.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physics and Chemistry of Minerals|
|State||Published - Aug 1992|
ASJC Scopus subject areas
- Materials Science(all)
- Geochemistry and Petrology