Structure and diffusion in simulated liquid GaAs

Department of Applied Physics, Institute of Technology, National University of Hochiminh City, 268 Ly Thuong Kiet Str., Distr. 10, Hochiminh City, Vietnam

Corresponding author: thuhanhsp@gmail.com

Received: 14 June 2009
Accepted: 20 November 2009
Published online: 16 February 2010

Abstract

Structure and diffusion of Ga and As ions in simulated liquid GaAs have been studied in a model containing 3000 ions under periodic boundary conditions via molecular dynamics simulation (MD). The microstructure of systems has been analyzed through partial radial distribution functions (PRDFs), coordination number distributions, bond-angle distributions and interatomic distances. We found that calculated data agree well with the experimental ones. Temperature dependence of these distributions was obtained. Caculations show that liquid GaAs model with a real density at 5.3176 g cm^-3 has a distorted tetrahedral network structure with the mean coordination number Z_As-Ga ≈ 4. Diffusion constant D in system has been calculated over temperatures ranged from 5000 K down to 1500 K. Calculations show that the temperature dependence of the diffusion constant D shows an Arrhenius law at relatively low temperatures above the melting point and it shows a power law, D ∼ (T - T_c)^γ, at higher temperatures.