COORDINATION OF EU3-GLASS BY X-RAY-DIFFRACTION( IONS IN A PHOSPHATE)

Two vitreous samples, 0.9 Zn(PO3)2 . 0.1 Eu(PO3)3 and pure zinc metaph osphate, were examined by X-ray diffraction to determine the local env ironment of the Eu3+ ion. Using a difference procedure involving the r adial functions of the two glasses, the results indicate that the rare -earth ion is surrounded on average by a polyhedron of about 7.4 oxyge ns at 2.36 angstrom and about 1.6 oxygens at 2.68 angstrom. A possible different coordination of the zinc ion in the two samples, suggested by the experimental findings, is discussed.