Dewetting of pulsed-laser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steady-state bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquid-liquid and liquid-gas interfaces due to this h-dependent temperature, which, in turn, is strongly influenced by the h-dependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the non-isothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational non-linear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including core-shell, embedded, or stacked nanostructure morphologies.
Applied Mechanics | Fluid Dynamics | Materials Science and Engineering | Nanoscience and Nanotechnology | Non-linear Dynamics | Numerical Analysis and Computation | Partial Differential Equations | Transport Phenomena
Recommended Repository Citation
Khenner, Mikhail; Yadavali, Sagar; and Kalyanaraman, Ramki. (2011). Formation of organized nanostructures from unstable bilayers of thin metallic liquids. Physics of Fluids, 23.
Original Publication URL: https://works.bepress.com/mkhenner/12/download/
Available at: https://digitalcommons.wku.edu/math_fac_pub/67
Applied Mechanics Commons, Fluid Dynamics Commons, Materials Science and Engineering Commons, Nanoscience and Nanotechnology Commons, Non-linear Dynamics Commons, Numerical Analysis and Computation Commons, Partial Differential Equations Commons, Transport Phenomena Commons