Diffusion in simulated liquid GeO2 under pressure

Abstract

Diffusion in simulated liquid GeO2 under pressure at different temperatures has been studied via isochore molecular dynamics (MD) simulation in a model containing 3000 particles with interatomic potentials that have weak Coulomb interaction and Morse-type short-range interaction. Calculations were done in models at three different densities of 3.65, 5.90 and 7.90 g/cm3. After intensive testing we found that the temperature dependence of the diffusion constant of atomic species in liquid GeO2 shows an Arrhenius law at relatively low temperatures, and at higher temperatures it shows a power law, D∼(T-Tc)γ, with an exception for models at a very high density of 7.90 g/cm3. Specific features of diffusion in liquid GeO2 compared with those observed in other strong liquids such as SiO2 or in other GeO2 models have been observed and discussed. © 2007 Elsevier B.V. All rights reserved.