Applicability of the Molecular Dynamics Technique to Simulate the Vitreous Silica Surface

Abstract

Vitreous silica (V-SiO₂) has been of technological importance for many years in the ceramics and glass industries and, more recently, in catalysis, microelectronics, fiber optics and nuclear radiation waste containment. Because of its importance in a number of diverse areas, V-SiO₂ has been the subject of a large number of experimental and theoretical studies aimed at determining the properties and structure of this material. In recent years, the molecular dynamics (MD) computer simulation technique has been used to determine the structural and dynamic properties of V-SiO₂ and silicate glasses at the atomic level [1–6]. In most of these MD simulations the modified Born-Mayer-Huggins equation has been used as the form of the pairwise interatomic potential function, although other potentials have been used [6,7]. The Born-Mayer-Huggins potential, being most suited for ionic systems, has also been used in simulations of alkali halides and BeF₂ [8–11]. Although V-SiO₂ is about 50% covalent, the modified Born-Mayer-Huggins equation can be considered as an effective potential in stimulations of vitreous silica which reproduces a number of structural and dynamic features with surprisingly reasonable accuracy.