Alkali aluminosilicate glasses

Y. Cao and A.N. Cormack. A structural model for interpretation of an anomaly in alkali aluminosilicate glasses at Al/alkali = 0.2-0.4. In H. Jain and D. Gupta, editors, Diffusion in Amorphous Materials, pages 137-151, Warrendale, PA, 1994. The Minerals, Metals and Materials Society. 

Mixed Alkali Effect in Alkali Silicate and Alkali Aluminosilicate Glasses... 

Fig. 1.44. Simplified ternary phase diagram of alkali aluminosilicate glass compositions that were tested to obtain glasses suitable for microstructuring with thermal expansion coefficients a that match those of Si, GaAs, Ni or Cu [128], Point A symbolises (not quantitatively) the composition of FS 21-glass. Prom A to R1 and R2 a decreases, from A to R4, R5, R6 and R7 a increases, from A to R3 a does not change remarkably...

Pederson, L. R., McGrail, B. P., McVay, G. L., Petersen-Villalobos, D. A. Settles, N. S. 1993. Kinetics of alkali silicate and aluminosilicate glass reactions in alkali chloride solutions Influence of surface charge. Physics and Chemistry of Glasses, 34, 140-148. 

It is generally accepted that aluminum is tetrahedrally coordinated in aluminosilicate glasses and melts, provided that cations such as alkali metals or alkaline earth metals are present in sufficient amounts to charge compensate the replacement of Si by AF+ [i.e., Si + —> AP" -t- (1/ )M" +, where monovalent or divalent M ions occur in nonframework sites associated with the tetrahedral aluminosilicate framework]. Experimental data for aluminosilicate glasses derived from both low-angle x-ray-scattering experiments and EXAFS studies show that as aluminum is substituted for silicon, the average T (tetrahedrally coordinated ion) -O bond... 

Figure 14. Deviation from additivity of diffusion activation energy in mixed alkali silicate and aluminosilicate glasses.

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