Phase-change phenomena during electron-beam heating:: Molecular dynamics simulations

In this paper, a computational study of a phase-change process during field emission induced heating is presented. Molecular dynamics (MD) simulations are performed to study the heating effect on a thin film of gold (the workpiece) when an electron beam from the tip of a carbon nanotube (CNT) hits the surface of the workpiece. A Monte Carlo method is adapted to solve the electron-beam Boltzmann transport equation to determine the electron distribution inside the workpiece. A hybrid approach is implemented to couple the two temperature model with MD simulations. The results of these simulations provide insight into the phase change during surface processing with an electron beam down to the atomic level. An order parameter and a radial distribution function are used to characterize the transition point at which the material changes phase. The results show that complete melting of the workpiece can be achieved with an array of CNTs with realistic experimental conditions.