Structure and dynamics of liquid and amorphous Al₂O₃.2SiO₂

¹ Dept. of Physics, Institute of Technology (polytechnic), National Univ. of HCM City, 268 Ly Thuong Kiet, Distr. 10, HochiMinh City, Vietnam
² Dept. of Physics and Comp. Physics Lab., College of Natural Sci., National Univ. of HCM City, Vietnam

Corresponding author: vvhoang2002@yahoo.com

Received: 9 May 2006
Revised: 4 September 2006
Accepted: 11 October 2006
Published online: 22 November 2006

Abstract

Structural properties of liquid and amorphous Al₂O₃.2SiO₂ (denoted as AS2) have been studied in a model containing 3025 particles under periodic boundary conditions with the Born-Mayer type pair potentials. Models have been obtained by cooling from the melt via molecular dynamics (MD) simulation. Structural properties of an amorphous model obtained at the temperature of 350 K have been analyzed in details through the partial radial distribution functions (PRDF), coordination number distribution, bond-angle distributions and interatomic distances. Calculations show that calculated data agree well with the experimental ones and with those obtained previously in other simulation works. The evolution of structure upon cooling from the melt was observed and discussed. We found a clear evidence of the existence of triclusters in the system. Diffusion constant of particles has been calculated and discussed. Calculations presented that the temperature dependence of diffusion constant D of components in the system shows an Arrhenius law at temperatures ranged from 2450 K to 4200 K and it shows a power law, , at higher temperatures.