STRUCTURE OF GEL MATERIALS IN THE SYSTEM CE2O3-AL2O3-P2O5

By using the sol-gel method, amorphous materials have been obtained in the Ce2O3-Al2O3-P2O5 system. Their phase formation and microstructura l changes have been investigated as a function of thermal treatment in the temperature range of 300-1400 degrees C by X-ray diffraction, inf rared spectroscopy and transmission electron microscopy. It is establi shed that gels containing Ce3+ possess high thermal stability. Accordi ng to the X-ray data, they are amorphous up to 500 degrees C. After cr ystallization, phases characteristic of the Ce3+ ions are present. The network of the gel materials is built up from PO4 phosphate complexes , by contrast with the gel products containing Ce4+.