resumo
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.
categoria
Materials Science, Ceramics
autores
Gaddam, A; Allu, AR; Fernandes, HR; Stan, GE; Negrila, CC; Jamale, AP; Mear, FO; Montagne, L; Ferreira, JMF
nossos autores
Allu Amarnath Reddy
Estudante de doutoramentoAnuraag Gaddam
Investigador Auxiliar
Atul Prabhakar Jamale
Investigador Júnior
Hugo Alexandre Gonçalves da Rocha Fernandes
Investigador Júnior
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)Grupos
G1 - Materiais Porosos e Nanossistemas
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
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