Study Of Rehydration Process Of Alumina Containing Cerium Doped Silica Gels By Ultraviolet, Visible And Ftir Spectroscopy

Alumina containing Ce doped silica xerogel and glasses were prepared by sol-gel processing at 500-1000 deg C under oxygen atmosphere. The partially densified gels were kept at 80% relative humidity for ageing and spectroscopic properties of the rehydrated partially densifed gels were mainly studied by absorption and FTIR spectroscopy. With ageing time the generation of absorption bands of Ce3+ ions suggested the change of local symmetry of the Ce ions. Finally, fourfold splitting was observed for Ce3+ after 60 days indicating eight coordinated water complexes like dodecahedral complexes having symmetry group D2d.