About an order of liquid-liquid phase transition in simulated liquid Al2O3

We investigate the pressure-induced structural transformation in liquid Al2O3 by molecular dynamics (MD) method. Simulations were done in the basic cube under periodic boundary conditions containing 3000 ions with Born-Mayer type pair potentials. Structure of liquid Al2O3 model with the real density and at the ambient pressure is in good agreement with Landron's experiment. In order to study the liquid-liquid phase transition, twelve models of liquid alumina at the temperature of 2500 K and at densities ranged from 2.80 to 5.0g/cm3 have been built. The microstructure of Al2O3 systems has been analyzed through pair radial distribution functions, coordination number distributions and interatomic distances. And we found a clear evidence of structural transition in liquid alumina from a tetrahedral to an octahedral network. The order of liquid-liquid phase transition in liquid alumina has been discussed.