Mixed oxides of the type MO 2(fluorite)-M 2O 3. V. Phase studies in the systems ZrO 2M 2O 3 (M = Sc, Yb, Er, Dy)

Results of phase studies on the systems ZrO ₂M ₂O ₃ (M = Sc, Yb, Er, Dy) are reported. Room-temperature X-ray diffraction of quenched and annealed samples is the main technique used, and the difficulties inherent in this approach to the determination of phase equilibria are discussed. Many of the data so obtained probably relate to metastable states, the nature of which is discussed in the light of structural information on ordered intermediate phases in the ZrO ₂Sc ₂O ₃ and ZrO ₂Yb ₂O ₃ systems. Some speculations on the question of the stability and structure of grossly nonstoichiometric phases observed in various composition regions of these systems are made. A. The System CeO ₂Y ₂O ₃.

B. The Systems CeO ₂M ₂O ₃ (M = La,Nd,Sm,Gd,Dy,Ho,Yb) ( 2).

Part III. Crystal Structures of the Intermediate Phases Zr ₅Sc ₂O ₁₃ and Zr ₃Sc ₄O ₁₂ ( 3). Part IV. J. Solid State Chem., preceding paper.