Simulated structural and thermal properties of glassy and liquid germania.
Structural, dynamical, and thermal properties of germanium dioxide are investigated with classical molecular dynamics simulations from the amorphous to the liquid state. Pair correlation functions and coordination numbers are computed under pressure change and show the progressive conversion of the tetrahedral network into an octahedral network, in agreement with experiments. The thermodynamical behavior of the liquid is investigated by means of an equation of state that allows a precise estimation of the compressibility. At low temperature, the diffusion constant D shows an Arrhenius law that progressively deviates when the temperature is increased. The overall comparison with simulated silica permits finally to outline not only the differences in the physical behavior of these two similar systems but also to stress the limitation of the employed germania potential.
Micoulaut
M
M
Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, Université Pierre et Marie Curie, Boite 121, 4, Place Jussieu, 75252 Paris Cedex 05, France.
Guissani
Y
Y
Guillot
B
B