resumo
The alleged formation of La-clusters in silicate glasses has received an overall consensus. However, recent and the current experimental results do not support this hypothesis for the structural role of La2O3 in glasses. Therefore, here we propose a new model for the assignment of the peaks in NMR spectra. All the experimental results here reported could be consistently explained by ascribing to La2O3 a network modifier role. Further, the proposed model could also explain the network modifier role of La2O3 in silicate glass compositions reported in literature where it was originally ascribed to form La-clusters. The La2O3 mitigated the LLPS due to increased entropy from the increasing number of different types of Q(n) structural units.
palavras-chave
LITHIUM DISILICATE GLASS; MOLECULAR-DYNAMICS SIMULATION; NUCLEAR-MAGNETIC-RESONANCE; LA2O3-NA2O-SIO2 GLASSES; CRYSTALLIZATION; SODIUM; MELTS; NMR; MICROSTRUCTURE; SPECTROSCOPY
categoria
Materials Science
autores
Gaddam, A; Fernandes, HR; Tulyaganov, DU; Ferreira, JMF
nossos autores
Anuraag Gaddam
Investigador Auxiliar
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
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the Fundacao para a Ciencia e a Tecnologia (FCT)/Ministerio da Ciencia, Tecnologia e Ensino Superior (MCTES) and when appropriate co-financed by Fundo Europeu de Desenvolvimento Regional (FEDER) under the PT2020 Partnership Agreement. Hugo R. Fernandes is grateful for the Post-Doctoral Grant (SFRH/BPD/110883/2015) from the Fundacao para a Ciencia e a Tecnologia (FCT), Portugal.