Molecular dynamics study on structure and properties of liquid and amorphous Al2O3

Abstract

Structure and thermodynamics properties of liquid and amorphous Al 2O3 have been investigated by Static Relaxation (SR) and Molecular Dynamics (MD) methods. Simulations were done in the basic cube under periodic boundary conditions containing 3000 ions with Born-Mayer type pair potentials. Structure of liquid and amorphous Al2O3 models is in good agreement with experiment. The microstructure of Al 2O3 system has been analyzed through pair radial distribution functions, coordination number distributions, interatomic distances or pore distribution (for amorphous state only). Temperature dependence of the pore distribution in amorphous Al2O3 was obtained. A thermal expansion coefficient and self-diffusion constants have been calculated. The temperature dependence of diffusion constants D in liquid Al 2O3 shows an Arrhenius law with activation energies which are close to experimental ones for liquid SiO2.