The diffusion coefficient in a melt was calculated for temperatures ranging from 1550 to 1900K by using molecular dynamics simulations which were based upon a modified Stillinger-Weber interatomic potential. The temperature dependence of the calculated diffusion coefficient could be described by:

D(cm2/s) = 3.8 x10-4exp[-0.27(eV)/kT]

The viscosity of the melt, which was related to the diffusion constant, was also estimated by using the Eyring relationship. It was found that the calculated viscosity agreed well with experimental data which were obtained by using an oscillating cup method; except at temperatures ranging from 1550 to 1750K.

K.Kakimoto: Journal of Applied Physics, 1995, 77[8], 4122-4