Molecular dynamics of liquid Zirconia: effect of pressure

Abstract

This paper carefully examined the influence of pressure within the range of (0 – 20) GPa on the selfdiffusion coefficients of zirconium and oxygen in cubic zirconia by a molecular dynamics (MD) simulations at a temperature of 3000 K using 96 -1500 particles. Data obtained showed that, at 96 particles the self-diffusion coefficients decreased from 1.60 x 10^-4 (Å2/ps) to 0.76 x 10^-4 (Å2/ps) between 0.0 GPa and 20.0 GPa. As the pressure is increased, the self-diffusion coefficient for zirconium and oxygen atoms decreases. Particularly, in the region of high pressure, the decrease in selfdiffusion coefficient for oxygen is nonlinear. This might be as a result of instability associated with large systems where one oxygen atom moves over the maximum potential of another oxygen atom. This is consistent with previous MD studies for oxygen in liquid SiO₂. The pair correlation function was found to increase with pressure. These thermo physical properties find practical applications in the electro ceramic industry.

Keywords: molecular dynamics, self-diffusion coefficient, liquid zirconia, pair correlation.