SIMULATION OF TEMPERATURE-INDUCED PHASE TRANSITION IN AMORPHOUS A12O3

Abstract

We investigate the temperature-induced structural transition in amorphous Al2O3 by molecular dynamics method. Simulation were done in the basic cube under periodic boundary conditions containing 3000 ions with Born-Mayer type pair potentials. Structure of model with the real density is in good agreement with Lamparter's experimental data. The compressed model at the density of 5.00g/cm was heated up from O0K to 18200K. The temperature of the system was increasing linearly in time from the zero temperature as r(t) = T0 +γt, where γ is the heating rate. The microstructure of Al2O3 systems has been analyzed through pair radial distribution functions, coordination number distributions, interatomic distances and bond-angle distributions. We have observed the temperature-induced phase transition in the amorphous alumina from an octahedral to a tetrahedral network structure. Such transition occurred at anywhere around 1200°K.