Structural studies on TeO2-PbO glasses

Binary tellurite-based glasses in the TeO2-PbO system were prepared and its structure investigated by means of Raman Scattering and X-ray Absorption S pectroscopy. Both spectroscopies indicate strong modifications of the first coordination shell around tellurium atoms when the PbO content increases r evealing for lead its glassy network modifier role. Also, Pb L-3-edge EXAFS measurements reveal this structural role played by lead atoms, but the pre sence of a medium range order contribution indicates that lead also partici pates to the glassy network formation. (C) 2001 Elsevier Science Ltd. All r ights reserved.