ULTRAVIOLET-ABSORPTION AND FLUORESCENCE-SPECTRA OF CERIUM AND THE EFFECT OF GLASS COMPOSITION

The absorption, excitation and emission spectra of the Ce3+ ion have b een recorded in the Na2O-B2O3 and Na2O-P2O5 glass systems. Previous da ta for halide and other environments indicate the potential of Ce3+ as a probe for measuring the optical basicity of glass and provide the n ecessary constants for its calculation. When these calculations are ma de for the borate glasses the optical basicity trend is almost identic al with that of Pb2+ which is a traditional probe for optical basicity measurements. It is apparent that Ce3+, like Pb2+, changes its site p osition over a composition range of approximately 15-20 mol% Na2O. How ever the behaviour of Ce3+ in the phosphate glasses is in marked contr ast. There is little resemblance to rite behavior of the Pb2+ probe an d it is probable that Ce3+ forms phosphato complexes which are only sl ightly affected by the glass basicity.