Heat capacity of stoichiometric Al2MnO4 spinel between 2 and 873 K

The heat capacity of stoichiometric Al2MnO4 spinel was measured from 2 to 873 K. These data are used to evaluate the entropy of this compound at 298.15 K and to propose a Gibbs energy function which was extrapolated to higher temperatures. Previously measured and assessed values for this compound are compared and the possible impact on the pseudo-binary Al2O3-MnO phase diagram is discussed. If it is assumed that all solid phases are stoichiometric and described by the compound energy model, and the liquid is described by the Kappor-Frohberg-Gaye quasi-chemical model, the proposed Gibbs energy model of the Al2MnO4 spinel corroborates the formation of two eutectic reactions in the Al2O3-MnO pseudo-binary phase diagram. (C) 2011 Elsevier Ltd. All rights reserved.