Silicate glasses computation

Huang, C. (1990) Characterization of the Structure and Transport Properties of Alkali Silicate Glasses Computer Simulation, PhD Thesis, Alfred University. 

Computer simulations suggest (Kanzaki 1997) that the major bottleneck responsible for the activation energy of ca. 100 kJ/mole for diffusion of H2O in polymerized silicate glasses/melts is related to the passage of such a molecule through a... 

Computer simulation proved to be an excellent tool to study a large variety of problems. Stmctore of solids and interfacial processes were largely studied by numerical simulations of the corresponding real systems [49-52]. The specific cases of bulk silica and silicate glasses were reviewed quite recently [53]. Amorphous silica was the material chosen to study by computer simulation in several cases [41,54-56]. 

Because of its non-crystalline nature, the structure of glass has largely resisted attack from the usual range of experimental probes, (although recent studies have begun to break down this resistance). This breakdown has been substantially aided by the application of computer simulation methods, which have been able to probe the structure at the atomic level. In this chapter, the technique of molecular dynamics will be described and its application to the structure of silicate glasses discussed. 

Huang, C. and Cormack A. N. (1991) Computer Simulation Studies of the Structure and Transport Properties of Alkali Silicate Glasses, in L. D. Pye, W. C. LaCourse and H. J. Stevens (eds.). Physics of Non-crystalline Solids, Taylor Francis, pp. 31-35. 

Vassal, B., Greaves, G. N., and Marten, P. T. (1991) Computer simulation Study of the Mixed Alkali Silicate Glasses NaxRbi-xSi02.5, Trans. Am. Crystallogr. Assoc.,27, 323-329. 

Angell CA, Cheeseman PA, Tamaddon S (1982a) Pressure enhancement of ion mobilities in hquid silicates from computer simulations studies to 800 kilobars. Sci 218 885-887 Angell CA, Cheeseman PA, Tamaddon S (1982b) Computer simulation studies of migration mechanisms in ionic glasses and liquids. J de Physique C9 381-385... 

Figure 13. Comparison of the experimental and computer-simulated spectra for potassium silicate glass (K20-4Si02). The upper trace represents the experimental spectrum after subtracting the broad underlying resonance. The lower trace is the computed best-fit spectrum (for the central fine-structure transition) with g = 2.0, A g is = -87 G, Do/gpu = 220 G, = 70 G, AZ)/gpB = 80 G, AF/gpe = 30 G, v = 8.9 GHz, A5pp = 7 G (Lorentzian line-shape). Adapted with permission from Khava and Purans (1980).

Computer simulations support the claim of Griscom and Griscom (1960) that the broad resonance does not arise firom non-central fine-structure transitions, since the contribution of these transitions to the total EPR spectrum is, in fact, insignificant to accoimt for the observed background resonance (see Figure 16.) As seen firom Figure 7, the peak-to-peak intensities of the broad resonance relative to sharp central features are about 3.3 and 4.0, respectively, for the phosphate and silicate glasses. 

Computational Modeling of Silicate Glasses A Quantitative Structure-Property Relationship Perspective... 

A. Pedone, G. Malavasi, A.N. Cormack, U. Segre, M.C. Menziani, Elastic and dynamical properties of silicate glasses from computer simulations techniques. Theor. Chem. Acc. 120, 557-564(2008)... 

C. Huang, A.N. Cormack, Computer simulation studies of the structure and transport properties of alkali silicate glasses. Physics of Non-CrystaUine Solids (Taylor Francis, Cambridge, 1992), pp. 31-35... 

M. Pota, A. Pedone, G. Malavasi, C. Durante, M. Cocchi, M.C. Menziani, Molecular dynamics simulations of sodium silicate glasses optimization and Emits of the computational procedure. Comput. Mater. Sd. 47(3), 739-751 (2010)... 

E.A. Leed, C.G. Pantano, Computer modeling of water adsorption on silica and silicate glass fracture surfaces. J. Non-Cryst. Solids 325(1-3), 48-60 (2003)... 

Silicate glass was textured using a CO2 laser [330]. The texturing is used to fabricate computer discs of high specific information density made from glass substrates. Laser pulses create a nanotexture on a surface of a glass disc. The process is based on rapid thermal cycles to manipulate the transformation temperature and finally the microstructure of the glass in the zone affected by the heat. 

---