Effect of Surface Interatomic Potential on Thermal Accommodation Coefficients Derived from Molecular Dynamics

This
work investigates how the interatomic surface potential influences
molecular dynamics (MD)-derived thermal accommodation coefficients
(TACs). Iron, copper, and silicon surfaces are considered over a range
of temperatures that include their melting points. Several classes
of potentials are reviewed, including two-body, three-body, and bond-order
force fields. MD-derived densities and visualization of the surfaces
are used to explain the differences in the parameterizations of these
potentials within the context of gas–surface scattering. Finally,
TACs are predicted for a range of gas–surface combinations,
and recommended values of the TAC are selected that take into account
the robustness and uncertainties of each of the considered parameterizations.
Further, it is observed that there is a significant change in the
TAC about phase changes that must be taken into account for applications
with a large range of surface temperatures.