Phase equilibria in systems Ag2MoO4-Ln2(MoO4)3-Hf(MoO4)2, Ln = Nd, Gd, Tb, Dy

X-ray diffraction study of solid-state interaction in the Ag2MoO4-Ln2(MoO4)3-Hf(MoO4)2 (Ln = Nd, Gd, Tb, Dy) systems was performed. Under the experimental conditions, the formation of triple molybdates was not detected. Quasi-binary sections were identified and a subsolidus phase diagrams of the studied systems was constructed. As the temperature rises to 580°C, decomposition is observed in sections with the participation of Ag2Hf(MoO4)3. In the systems under study, stabilization of the Hf(MoO4)2 type of low-temperature modification of zirconium molybdate is observed. By the image of phase equilibria, the systems are divided into four types.