Controlling Nanoparticles Formation in Molten Metallic Bilayers by Pulsed-Laser Interference Heating

¹ Department of Mathematics, Applied Physics Institute, Western Kentucky University, Bowling Green, KY 42101
² Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN 37996
³ Department of Chemical and Biomolecular Engineering, Department of Materials Science and Engineering, Sustainable Energy Education Research Center, The University of Tennessee, Knoxville, TN 37996

^∗ Corresponding author. E-mail: mikhail.khenner@wku.edu.

Abstract

The impacts of the two-beam interference heating on the number of core-shell and embedded nanoparticles and on nanostructure coarsening are studied numerically based on the non-linear dynamical model for dewetting of the pulsed-laser irradiated, thin (< 20 nm) metallic bilayers. The model incorporates thermocapillary forces and disjoining pressures, and assumes dewetting from the optically transparent substrate atop of the reflective support layer, which results in the complicated dependence of light reflectivity and absorption on the thicknesses of the layers. Stabilizing thermocapillary effect is due to the local thickness-dependent, steady-state temperature profile in the liquid, which is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Linear stability analysis of the model equations set for Ag/Co bilayer predicts the dewetting length scales in the qualitative agreement with experiment.