The effect of synthesis conditions on the structure of compounds formed in the Dy2O3–TiO2 system

Abstract

Crystallization and phase transition processes taking place in the Dy 2 O 3 -TiO 2 system during the isothermal annealing of the precursors synthesized by co-precipitation were studied. The phase composition of the obtained powders is determined by not only the chemical composition of the precursor (Dy 2 O 3 : TiO 2 ratio) and annealing temperature but also by the procedure of precursor synthesis determining the uniformity of Dy and Ti distribution in the precursor precipitate. Higher homogeneity of precursor particles provides the formation of almost single-phase nanocrystaline dysprosium titanate (Dy 2 TiO 5 , Dy 2 Ti 2 O 7 ) powders at annealing temperatures of 800-1000°C.

Fluorite-pyrochlore phase transition in nanostructured Ln2Hf2O7 (Ln = La-Lu)

“…The synthesis from solutions has the advantage of yielding a highly homogeneous cation distribu-95 tion within the precursor prepared by the coprecipitation, and allows production of almost singlephase nanocrystalline powders with predetermined composition at lower temperatures [40]. Thus this method is appropriate for studying the evolution of 100 crystalline phases and possible polymorphic transformations during the process of Ln 2 M 2 O 7 synthesis.…”