Chemical and Phase Transformations during the Synthesis of Cs[MgR 0.5 P 1.5 O 6 ] (R = B, Al, Fe) Complex Oxides from Metal Chlorides

Cesium-containing complex oxides Cs[MgR0.5P1.5O6], where R = B, Al, or Fe, were prepared from solutions containing H3BO3, metal nitrates, and H3PO4/NH4H2PO4. The chemical and phase transformations occurring during the synthesis of these oxides were elucidated by differential thermal analysis (DTA) and X-ray powder diffraction (XRD. Optimal synthesis parameters were found. The boron compound was found to be formed at 800°C, and the aluminum and iron compounds, at 1200°C. All compounds have the pollucite structure (cubic system, space group I4132). A comparative analysis of the synthesis of complex oxides under study from various precursors that differed from one another in metal and phosphorus chemical species was carried out.