The environment of CA ions in silicate glasses

Local and medium range structure of erbium containing glasses: A molecular dynamics study

“…The model has been validated by comparing the computational data with the values derived by experimental and theoretical analysis performed on similar glasses. A general good agreement has been observed confirming the validity of the numerical model used in this work [18,22,19,[26][27][28][29][30][31][32]. However the SiSi average bond distance is quite larger than the value of 3.077 Å obtained from neutron diffraction [16,22].…”

Optical and structural properties of calcium silicate glasses

“…After a brutal increase the ratio of calcium in C 1 sites stays nearly constant for calcium concentrations above 46%. As already reported in the literature [9,10,18,21,22], in glass compositions around the metasilicate one, a majority of the calcium cations occupies CaO 6 distorted octahedra surrounded by chains of SiO 4 tetrahedra, a structural configuration that is similar to that of wollastonite crystal (CaSiO 3 ) [23]. The C 1 sites correspond to this type of configuration.…”

“…Most of the other studies have been limited to a single composition, generally the calcium metasilicate one. One can cite NMR measurements [14][15][16][17], X-ray diffraction [18][19][20], and neutron diffraction [21,22]. There is a large consensus in the literature to say that the local order around a majority of calcium cations in the metasilicate glass is similar to those in the wollastonite crystal (CaSiO 3 ) [23], i.e., [9,10,18,21,22].…”

“…There is a large consensus in the literature to say that the local order around a majority of calcium cations in the metasilicate glass is similar to those in the wollastonite crystal (CaSiO 3 ) [23], i.e., [9,10,18,21,22]. The remaining calcium cations have significantly longer bonds than in the crystal [21] and may be part of regions where silica ordering holds in small distance scale [22]. Mihailova et al [10] also put forward the possibility of the existence of two representative clusters in the Ca-O network, which differ in the strength of the interaction between calcium and silicon atoms.…”

Sodium tracer diffusion in glasses of the type (CaO·Al2O3)x(2SiO2)1−x

“…The number of systematic investigations on property changes in 'fully polymerized glasses' as a function of their cationic composition is relatively small [9][10][11][12][13]. This article focuses on transport property changes in 'fully polymerized glasses' with the glass composition.…”