Pressure-Induced Structural Analysis of ZrO₂ Nanoparticle: Molecular Dynamics Simulation

The nanoparticles of cubic ZrO₂ containing 324, 768, and 1500 atoms from 1 GPa to 20 GPa are investigated by using molecular dynamics simulations. The hydrostatic pressure is employed in the system, while an ideal gas is used as the pressure medium and thermostat in the molecular dynamics simulations. Using this method, we study the pressure-induced structural transformation from the four-coordinated to six- or eight-coordinated Zr–O arrangements during the pressurized process. The total correlation function T(r), coordination number and bond-angle distribution are all calculated in order to analyze the structural properties of ZrO₂ nanoparticles. The ZrO₂ nanoparticles containing 324 and 768 atoms have only one structural transition, which take place under 9∼10 GPa and 8∼11 GPa. The large nanoparticle with 1500 atoms undergoes two structural transitions. The first structural transformation occurs at 7∼8 GPa and the other is at 14∼16 GPa with the increase in pressure.