[Zurück]

T. Ivas, A. Grundy, E. Povoden-Karadeniz, L.J. Gauckler:
"Phase diagram of CeO2-CoO for nano sized powders";
CALPHAD - Computer Coupling of Phase Diagrams and Thermochemistry, 36 (2012), S. 57 - 64.

The CALPHAD (Calculation of Phase Diagrams) framework to calculate the thermodynamic properties of multicomponent systems is extended to account for the change in thermodynamic properties by the size effect in small particle systems. We have applied this framework to the CeO2-CoO binary in order to elucidate the liquid sintering like fast densification at unusually low temperatures of cobalt oxide doped ceria. The phase diagram for 5 nm particles shows a significant drop of the eutectic from 1645 °C to 1327 C. The size-dependent thermodynamic stability of intergranular films is examined and melting temperature of 1180 C is found for 1 mol% CoO doped CeO2. These results can´t explain the unusual low sintering temperatures of 900-950 C, with a "liquid-sintering"-like characteristic that was previously experimentally observed.

http://dx.doi.org/10.1016/j.calphad.2011.10.005