Thermodynamic vaporization studies of the manganese oxide-yttria stabilized zirconia (YSZ) solid solution

Samples of the compositions (Zr0.85Y0.15)(1-x)MnxO(1.93-delta), 0.02 less than or equal to x less than or equal to 0.25, were prepared and characterized by means of XRD and SEM/EDX analysis. The vaporization of manganese oxide from the samples with x less than or equal to 0.18 was studied by Knudsen effusion mass spectrometry in the temperature range of 1539-1858 K. Partial pressures of gaseous Mn, MnO, and O-2 were determined over the samples investigated and thermodynamic activities of MnO in the samples evaluated at 1700 K. Chemical and phase compositions of the samples were determined after the vaporization measurements and the results obtained were correlated with the obtained values of the thermodynamic activity of MnO. The thermodynamic activities determined belong to the solubility range of manganese oxide in yttria stabilized zirconia. Moreover, thermodynamic data on the vaporisation of pure MnO(s) resulted. (C) 2003 Elsevier Ltd. All rights. reserved.