MAS-NMR investigations of the crystallization behaviour of lithium aluminum silicate (LAS) glasses containing P{sub 2}O{sub 5} and TiO{sub 2} nucleants

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.04.011· OSTI ID:21421530

Ananthanarayanan, A ^[1]; Kothiyal, G P ^[1]; Montagne, L ^[2]; Revel, B ^[2]

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1. Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
2. Universite Lille Nord de France - UMR CNRS 8181, USTL, 59655 Villeneuve d'Ascq (France)

Lithium aluminum silicate (LAS) glass of composition (mol%) 20.4Li{sub 2}O-4.0Al{sub 2}O{sub 3}-68.6SiO{sub 2}-3.0K{sub 2}O-2.6B{sub 2}O{sub 3}-0.5P{sub 2}O{sub 5}-0.9TiO{sub 2} was prepared by melt quenching. The glass was then nucleated and crystallized based on differential thermal analysis (DTA) data and was characterized by {sup 29}Si, {sup 31}P, {sup 11}B and {sup 27}Al MAS-NMR. XRD and {sup 29}Si NMR showed that lithium metasilicate (Li{sub 2}SiO{sub 3}) is the first phase to c form followed by cristobalite (SiO{sub 2}) and lithium disilicate (Li{sub 2}Si{sub 2}O{sub 5}). {sup 29}Si MAS-NMR revealed a change in the network structure already for the glasses nucleated at 550 {sup o}C. Since crystalline Li{sub 3}PO{sub 4}, as observed by {sup 31}P MAS-NMR, forms concurrently with the silicate phases, we conclude that crystalline Li{sub 3}PO{sub 4} does not act as a nucleating agent for lithium silicate phases. Moreover, {sup 31}P NMR indicates the formation of M-PO{sub 4} (M=B, Al or Ti) complexes. The presence of BO{sub 3} and BO{sub 4} structural units in all the glass/glass-ceramic samples is revealed through {sup 11}B MAS-NMR. B remains in the residual glass and the crystallization of silicate phases causes a reduction in the number of alkali ions available for charge compensation. As a result, the number of trigonally coordinated B (BO{sub 3}) increases at the expense of tetrahedrally coordinated B (BO{sub 4}). The {sup 27}Al MAS-NMR spectra indicate the presence of tetrahedrally coordinated Al species, which are only slightly perturbed by the crystallization. - Graphical abstract: {sup 11}B MAS-NMR spectra of LAS glass heat treated at different temperatures, showing the evolution of the residual glass matrix during the crystallization treatment. High-field (18.8 T) NMR enables us to record high resolution spectra, from which the glass network modifications could be related to the formation of intermediate lithium silicate crystalline phases.

• OSTI ID: 21421530
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 6; Other Information: DOI: 10.1016/j.jssc.2010.04.011; PII: S0022-4596(10)00144-1; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM SILICATES
CERAMICS
CRISTOBALITE
CRYSTALLIZATION
DIFFERENTIAL THERMAL ANALYSIS
GLASS
HEAT TREATMENTS
LITHIUM PHOSPHATES
LITHIUM SILICATES
NMR SPECTRA
PHOSPHORUS OXIDES
QUENCHING
SILICON OXIDES
TITANIUM OXIDES
X-RAY DIFFRACTION
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
LITHIUM COMPOUNDS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOSPHATES
PHOSPHORUS COMPOUNDS
SCATTERING
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SPECTRA
THERMAL ANALYSIS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS