Chemical and Phase Transformations during the Synthesis of Cs[MgR0.5P1.5O6] (R = B, Al, Fe) Complex Oxides from Metal Chlorides

Abstract

Cesium-containing complex oxides Cs[MgR_0.5P_1.5O₆] (R = B, Al, Fe) are prepared from solutions containing H₃BO₃, metal chlorides, and H₃PO₄/NH₄H₂PO₄. The chemical and phase transformations that occur during the synthesis are elucidated by differential thermal analysis (DTA) and X-ray powder diffraction (XRD). Optimal synthesis parameters are determined. The oxides where R = B or Fe are formed at 800°C, those where R = Al are formed at 1100°C. All compounds crystallize in the pollucite-type structure (cubic system, space group I4₁32).