Unified interatomic potential for zircon, zirconia and silica systems

We report the development of a unified force field with high transferability and reliability to model both structures and mechanical properties of ZrSiO4, ZrO2 and SiO2 based on the success of the BKS potential for SiO2 1 (van Beest et al., Phys. Rev. Lett., 1990, 64, 1955). The thermal expansion, relative stability and phase transition properties are consistent with experimental data and DFT calculations. The zircon to reidite transition pressure is 6.7 GPa. Amorphization of zircon results in volume expansion of 11% and decrease in the bulk modulus of 60%. Si polymerization and Zr under-coordination were observed in amorphous ZrSiO4 and in the damage produced by a 10 keV Zr recoil in crystalline ZrSiO4. The upper limit of stored energy in amorphous ZrSiO4 is 140 kJ/mol.