title: Equilibrium and nonequilibrium molecular dynamics simulations of thermal conductance at solid-gas interfaces.
abstract: The thermal conductance at solid-gas interfaces with different interfacial bonding strengths is calculated through Green-Kubo equilibrium molecular dynamics (EMD) simulations. Due to the finite size of the simulation system, the long-time integral of the time correlation function of heat power across the solid-gas interface exhibits an exponential decay, which contains the information on interfacial thermal conductance. If an adsorbed gas layer is formed on the solid surface, it is found that the solid-gas interface needs to be defined at a plane outside the adsorbed layer so as to obtain the correct result from the Green-Kubo formula. The EMD simulation result agrees very well with that obtained from nonequilibrium molecular dynamics simulations. By calculating the average solid-gas interaction time as a function of solid-gas interaction strength, we find the incident gas atoms thermalize with the metal surface much more rapidly when the surface is covered by adsorbed gas molecules.
authors.affiliation: Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180, USA. liangz3@rpi.edu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liang
authors.forename: William
authors.initials: W
authors.lastname: Evans
authors.forename: Pawel
authors.initials: P
authors.lastname: Keblinski
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D005740:Gases / Q000737:chemistry*; D008956:Models, Chemical; D015233:Models, Statistical; D056004:Molecular Dynamics Simulation; D013499:Surface Properties; D013814:Thermal Conductivity
chemical_list: D005740:Gases