Pb LIII-edge EXAFS and XANES analyses on the structural environment of lead in PbO-Ga2O3 glasses

Pb LIII-edge absorption spectra of PbO-Ga2O3 glasses were analyzed and the local environment of lead in glasses was proposed. A single-shell fitting of Pb LIII-edge EXAFS (extended X-ray absorption fine structure) spectra of three PbO-Ga2O3 glasses showed that the Pb-O bond distances were between 0.229 and 0.231 nm with the oxygen coordination numbers between 3.3 and 3.5. Comparison of the absorption peaks in the pre-edge region of the Pb LIII-edge XANES (X-ray absorption near edge structure)spectra between glasses and other reference crystals indicated that the Pb2+ ions form either PbO3 or PbO4 polyhedra, These polyhedra are connected through either two- or three-coordinated oxygens similar to the configuration in PbSiO3 crystal. (C) 1999 Elsevier Science B.V. All rights reserved.