abstract
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.
keywords
LITHIUM DISILICATE GLASS; MOLECULAR-DYNAMICS SIMULATION; NUCLEAR-MAGNETIC-RESONANCE; LA2O3-NA2O-SIO2 GLASSES; CRYSTALLIZATION; SODIUM; MELTS; NMR; MICROSTRUCTURE; SPECTROSCOPY
subject category
Materials Science
authors
Gaddam, A; Fernandes, HR; Tulyaganov, DU; Ferreira, JMF
our authors
Anuraag Gaddam
Assistant 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
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.