On the Thermal Decomposition of Cerium(IV) Hydrogen Phosphate Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5

Cerium(IV) hydrogen phosphate Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5 has been prepared by hydrothermal treatment of gels obtained by hydrolysis of cerium-containing phosphoric acid solutions. The obtained compound and the products of its heating in a wide temperature range have been analyzed by X-ray powder diffraction analysis, IR spectroscopy, mass spectrometry of gaseous thermolysis products, and scanning electron microscopy. Thermal decomposition of the compound at temperature up to 1200°С has been refined. In particular, it has been shown that crystalline cerium(III) phosphate (CePO 4 ) forms upon heating of Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5 in air even at 600°C.