Raman scattering and molecular dynamic simulations investigation of lead metasilicate glass and supercooled liquid structures

Reference	Presenter	Authors (Institution)	Abstract
10-038	David Vieira Sampaio	Sampaio, D.V.(Federal University of São Carlos (UFSCar)); Picinin, A.(Federal University of São Carlos); Moulton, B.J.(Federal University of São Carlos (UFSCar)); Rino, J.P.(Federal University of São Carlos (UFSCar)); Zanotto, E.D.(Federal University of São Carlos (UFSCar)); Pizani, P.S.(Federal University of São Carlos (UFSCar));	Lead metasilicate glass (PbO.SiO2) is of considerable scientific interest because it shows an outstanding glass forming ability despite is very low SiO2 content. In this research, we performed a detailed investigation of PbO.SiO2 glass and supercooled liquid (SCL) structure by Raman scattering and Molecular Dynamics simulations. We correlated information obtained from these two techniques to construct a reliable picture of its structure at intermediate distances, and its variation from room temperature up to the melting point of the crystal phase. While the Raman scattering results were fundamental as a guide to the energy scale to validate the MD simulations, the simulations were the key to decide about the assignments of the Raman bands. From these highly synergistic results, we concluded that the lead metasilicate glass and SCL have two types of Q3 species that are related to the bimodal distribution of the Si-Pb pair correlation function. The temperature dependence of the Qn species was also investigated, for the first time, for this glass. A depolymerization of the silicate network was detected, which was correlated to the increase of Q0 and Q1 species with the simultaneous decrease of Q2 and Q3 species with increasing temperature. Q4 species were present in very small amounts.
<< Back