Elucidating the formation of Al-NBO bonds, Al-O-Al linkages and clusters in alkaline-earth aluminosilicate glasses based on molecular dynamics simulations
Ganisetti VNS, Gaddam A, Kumar R, Balaji S, Mather GC, Pascual MJ, Fabian M, Siegel R, Senker J, Kharton VV, Guénolé J, Krishnan NM, Ferreira JM, Allu AR (2019)
Publication Type: Journal article
Publication year: 2019
Journal
Book Volume: 21
Pages Range: 23966-23977
Journal Issue: 43
DOI: 10.1039/c9cp04332b
Abstract
Exploring the reasons for the initiation of Al-O-Al bond formation in alkali-earth alumino silicate glasses is a key topic in the glass-science community. Evidence for the formation of Al-O-Al and Al-NBO bonds in the glass composition 38.7CaO-9.7MgO-12.9Al2O3-38.7SiO2 (CMAS, mol%) has been provided based on Molecular Dynamics (MD) simulations. Analyses in the short-range order confirm that silicon and the majority of aluminium cations form regular tetrahedra. Well-separated homonuclear (Si-O-Si) and heteronuclear (Si-O-Al) cluster regions have been identified. In addition, a channel region (C-Region), separated from the network region, enriched with both NBO and non-framework modifier cations, has also been identified. These findings are in support of the previously proposed extended modified random network (EMRN) model for aluminosilicate glasses. A detailed analysis of the structural distributions revealed that a majority of Al, 51.6%, is found in Si-O-Al links. Although the formation of Al-O-Al and Al-NBO bonds is energetically less favourable, a significant amount of Al is found in Al-O-Al links (33.5%), violating Lowenstein's rule, and the remainder is bonded with non-bridging oxygen (NBO) in the form of Al-NBO (Al-O-(Ca, Mg)). The conditions necessary for the formation of less favourable bonds are attributed to the presence of a high amount of modifier cations in current CMAS glass and their preferable coordination.
Authors with CRIS profile
Involved external institutions
University of Aveiro / Universidade de Aveiro
Portugal (PT)
Central Glass and Ceramic Research Institute
India (IN)
Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen
Germany (DE)
Centre for Energy Research of the Hungarian Academy of Sciences
Hungary (HU)
Universität Bayreuth
Germany (DE)
Institute of Solid State Physics (ISSP) / Институт физики твердого тела
Russian Federation (RU)
Institute of Ceramics and Glass (ICV) / Instituto de Cerámica y Vidrio
Spain (ES)
Indian Institute of Technology (IIT), Delhi
India (IN)
Portugal (PT)
Central Glass and Ceramic Research Institute
India (IN)
Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen
Germany (DE)
Centre for Energy Research of the Hungarian Academy of Sciences
Hungary (HU)
Universität Bayreuth
Germany (DE)
Institute of Solid State Physics (ISSP) / Институт физики твердого тела
Russian Federation (RU)
Institute of Ceramics and Glass (ICV) / Instituto de Cerámica y Vidrio
Spain (ES)
Indian Institute of Technology (IIT), Delhi
India (IN)
How to cite
APA:
Ganisetti, V.N.S., Gaddam, A., Kumar, R., Balaji, S., Mather, G.C., Pascual, M.J.,... Allu, A.R. (2019). Elucidating the formation of Al-NBO bonds, Al-O-Al linkages and clusters in alkaline-earth aluminosilicate glasses based on molecular dynamics simulations. Physical Chemistry Chemical Physics, 21(43), 23966-23977. https://dx.doi.org/10.1039/c9cp04332b
MLA:
Ganisetti, Venkata Naga Sudheer, et al. "Elucidating the formation of Al-NBO bonds, Al-O-Al linkages and clusters in alkaline-earth aluminosilicate glasses based on molecular dynamics simulations." Physical Chemistry Chemical Physics 21.43 (2019): 23966-23977.
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