A critical evaluation of barium silicate glass network polymerization

Author(s)

Picinin, Benjamin J. A. ; Picinin, Adalberto ; Silva, Lais D. ; Doerenkamp, Carsten ; Lozano, Harold D. ; Sampaio, David ; Zanotto, Edgar D. ; Du, Jincheng S. ; Eckert, Hellmut ; Pizani, Paulo S.

• Document type: Journal article
• Source: Journal of Non-Crystalline Solids; v. 583, p. 19-pg., 2022-02-14.

Abstract

The state of polymerization in barium silicate glasses (xBaO.(1-x)SiO2 , 0.28 <= x <= 0.45) has been studied by both experiment (Raman, static and MAS Si-29 NMR spectroscopy) and molecular dynamics simulations (VashishtaRahman and Du-Cormack potentials). No a priori assumptions were made about the number of Qn species, specific mean polymerization nor presence or absence of 'free' oxygen species. This allowed us to test the relationships between these structural aspects.& nbsp;The Q(n) site interconversion equilibrium constants K-Q2 and K-Q3 were found to be 0.07 and 0.05 +/- 0.02 from static 29Si NMR, and 0.14 & PLUSMN;0.07 and 0.07 & PLUSMN;0.01 from 29Si MAS NMR, respectively.The Qn species distribution was used to determine the Raman scattering cross-sections for Q(1) , Q(2) and Q(3) as 1.01 +/- 0.15, ~1.1, and 1.14 & PLUSMN;0.04, respectively, although some compositional dependence was found. The Q4 cross-section displays a unique behavior approaching 0 at 38% BaO. This more accurate structural framework paves the way for future studies to establish meaningful structure-property relationships for these glasses. (AU)

• FAPESP's process: 16/18567-5 - Nuclei entrapment: the pre-nucleation structural ordering of homogeneous nucleating BaO-2SiO2 and CaO-SiO2 glasses
• Grantee: Benjamin John Albert Moulton
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/06649-0 - New Optical Materials based on Rare-Earth Doped Oxyfluoride Glasses and Ceramics: Structural Studies by Electron Paramagnetic Resonance Methods
• Grantee: Carsten Doerenkamp
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 16/15962-0 - Correlation between materials structure and dynamic and optical properties of (Ax, A'1-x)O + SiO2 (A, A' = Pb, Ni, Co, Fe, Cr) series: Raman scattering and molecular dynamics simulations
• Grantee: David Vieira Sampaio
• Support Opportunities: Scholarships in Brazil - Post-Doctoral