Deconvolution method of Si-29 MAS NMR spectra applied to homogeneous and phase separated lanthanum aluminosilicate glasses

作者：Diallo, Babacar^*; Allix, Mathieu; Veron, Emmanuel; Sarou Kanian, Vincent; Bardez Giboire, Isabelle; Montouillout, Valerie; Pellerin, Nadia

来源：Journal of Non-Crystalline Solids, 2019, 503: 352-365.

DOI：10.1016/j.jnoncrysol.2018.10.026

• Glass structure
• Phase separation
• Immiscibility
• Solid state NMR

The structural and microstructural properties of both homogeneous and phase separated lanthanum aluminosilicate (La2O3-Al2O3-SiO2 i.e. LaAS system) glasses were investigated. The microstructural observations and the structural characterization by X-ray Diffraction and by Nuclear Magnetic Resonance have highlighted the role of aluminum to favor a homogeneous vitreous aluminosilicate network by a high-level of Al/Si intermixing. A qualitative and simplified structure description is proposed from Si-29 nuclear magnetic resonance spectra assignment according to Q(n)(mAl) species by controlling the deviation of chemical parameters. According to this approach, a homogeneous distribution of non-bridging oxygen in the aluminosilicate network and Al-O-Al linkages are considered for homogeneous glasses with high Al/Si atomic ratio. Phase separated samples are characterized by a low Al/Si atomic ratio inducing spinodal or nucleation/growth phase separation according to the depolymerization level. Homogeneity degree of the samples is discussed according to the intermixing level between silicon tetrahedra and aluminum polyhedra as a function of the proportion of Q(n) and Q(n)(mAl) species.

• 出版日期2019-1-15
• 单位中国地震局