Hydrothermal Coarsening of CeO₂ Particles
Messing, Gary L.
The effects of reaction temperature (150-300 °C), chemical composition of the starting cerium salt (cerium nitrate and cerium chloride), and doping with trivalent cations (Sc3+ and Y3+) on the coarsening of CeO2 particles in dilute suspensions under hydrothermal conditions were investigated. The particle size was measured by x-ray line broadening and by transmission electron microscopy. The particle coarsening kinetics followed a parabolic law, indicating that the interfacial reaction (dissolution) was the rate-controlling step. Furthermore, the particle size distribution data can be well-described by the Lifshitz-Slyozov-Wagner theory of Ostwald ripening controlled by the interfacial reaction. Doping with 6 at.% Y3+ produced a significant reduction in the coarsening rate but almost no change in the activation energy. At the same concentration, Sc3+ was more effective than Y3+ in reducing the coarsening rate. Particles synthesized from a starting solution of cerium(III) chloride coarsened at a markedly slower rate than that for particles synthesized from cerium(III) nitrate. The mechanisms controlling the coarsening of the particles are discussed.
S. G. Lakhwani and M. N. Rahaman, "Hydrothermal Coarsening of CeO₂ Particles," Journal of Materials Research, Materials Research Society, Jan 1999.
The definitive version is available at http://dx.doi.org/10.1557/JMR.1999.0196
Materials Science and Engineering
Article - Journal
© 1999 Materials Research Society, All rights reserved.