Molecular dynamics simulation of mass transfer in molten silicon

The diffusion constant in a silicon melt is calculated using molecular dynamics simulation based on the modified Stillinger-Weber [Phys. Rev. B 31, 5262 (1985)] interatomic potential in the temperature range 1550 K<T<1900 K. Temperature dependence of the calculated diffusion constant can be expressed using the following equation: D=3.8×10^-4 exp(-0.27 eV/kT)cm²/s. Viscosity of the silicon melt, which correlates to the diffusion constant, is also estimated using Eyring's relation reported by S. Glasstone, K. J. Laidler, and H. Eyring [McGraw-Hill, New York (1941)]. The calculated viscosity correlates well with experimental data which were obtained by an oscillating cup method except in the temperature range from 1550 to 1750 K.