Role of vanadium oxide on the lithium silicate glass structure and properties. Issue 6 (4th February 2021)

• Record Type: Journal Article
• Authors: Gaddam, Anuraag; Allu, Amarnath R.; Fernandes, Hugo R.; Stan, George E.; Negrila, Catalin C.; Jamale, Atul P.; Méar, François O.; Montagne, Lionel; Ferreira, José M.F.
• Is Part Of: Journal of the American Ceramic Society. Volume 104:Issue 6(2021)
• Page Start: 2495
• Page End: 2505
• Publication Date: 2021-02-04
• Subjects: glass -- ionic conductivity -- lithium silicate -- structure -- vanadium/vanadium compounds; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.17671
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: The structural role of V in 28Li2 O–72SiO2 (in mol%) lithium silicate glass doped with 0.5 mol% V2 O5 was assessed using 29 Si and 51 V Nuclear Magnetic Resonance (NMR), Fourier‐transform infrared (FTIR), and X‐ray photoelectron (XPS) spectroscopy techniques. Despite the low amount of V2 O5 used, the structural information obtained or deduced from the statistical analysis of the NMR data could explain the evolution of glass properties after V2 O5 addition. The XPS results indicated that all vanadium exists in 5+ oxidation state. Both the 29 Si NMR and FTIR data point toward an increase in the polymerization of the silicate network, caused by the V2 O5 acting as network former, capable to form various Q V n tetrahedral units (for n = 0, 1, and 2) in the glasses. These Q V n units, which are similar to phosphate units, scavenge the Li + ions and cause the silicate network to polymerize. However, in an overall balance, the entire glass network is depolymerized due to the additional nonbridging oxygens contributed by the vanadium polyhedra. The addition of vanadium causes the network to expand and increases the ionic conductivity.