abstract
The structural role of V in 28Li(2)O-72SiO(2) (in mol%) lithium silicate glass doped with 0.5 mol% V2O5 was assessed using Si-29 and V-51 Nuclear Magnetic Resonance (NMR), Fourier-transform infrared (FTIR), and X-ray photoelectron (XPS) spectroscopy techniques. Despite the low amount of V2O5 used, the structural information obtained or deduced from the statistical analysis of the NMR data could explain the evolution of glass properties after V2O5 addition. The XPS results indicated that all vanadium exists in 5+ oxidation state. Both the Si-29 NMR and FTIR data point toward an increase in the polymerization of the silicate network, caused by the V2O5 acting as network former, capable to form various QVn tetrahedral units (for n = 0, 1, and 2) in the glasses. These QVn 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.
subject category
Materials Science, Ceramics
authors
Gaddam, A; Allu, AR; Fernandes, HR; Stan, GE; Negrila, CC; Jamale, AP; Mear, FO; Montagne, L; Ferreira, JMF
our authors
Allu Amarnath Reddy
PhD StudentAnuraag Gaddam
Assistant Researcher
Atul Prabhakar Jamale
Junior Researcher
Hugo Alexandre Gonçalves da Rocha Fernandes
Junior Researcher
José Maria da Fonte Ferreira
Retired ProfessorGroups
G1 - Porous Materials and Nanosystems
G3 - Electrochemical Materials, Interfaces and Coatings
G5 - Biomimetic, Biological and Living Materials
acknowledgements
DST-SERB, Grant/Award Number: ECR/2 018/000292; JECS trust, Grant/Award Number: 201478; Centro de Investigacao em Materiais Ceramicos e Compositos, Grant/Award Number: UIDB/50011/2020 and UIDP/50011/2020