SIMULATION OF AMORPHOUS-AMORPHOUS PHASE TRANSITION IN AMORPHOUS Al2O3

Abstract

We investigated the pressure-induced structural transformation in amorphous Al2O3 by Molecular Dynamics (MD) method. Simulations were done in cube under periodic boundary conditions containing 3000 ions with Born-Mayer type pair potentials. Structure of amorphous Al2O3 model with real density at ambient pressure is in good agreement with Lamparter's experiment. In order to study the amorphous-amorphous phase transition, six models of amorphous alumina at the temperature of 0 K and at densities ranged from 2.84 gcm-3 to 5.0 gcm-3 had been built. The microstructure of Al2O3 systems had been analyzed through pair radial distribution functions, coordination number distributions, interatomic distances and bond-angle distributions. Here we found clear evidence of a structural transition in amorphous alumina from a tetrahedral to an octahedral network upon compression.