A hybrid off-lattice kinetic Monte Carlo/molecular dynamics method for amorphous thin film growth

05 April 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

The ability to understand and model the growth of amorphous thin films on solid surfaces is essential to a wide range of industrial applications, from the deposition of wear-resistant coatings to the production of solar cells. Here, a three-dimensional (3D) hybrid off-lattice kinetic Monte Carlo-molecular dynamics (kMC/MD) algorithm is developed to study the growth of thin amorphous films on solid substrates over timescales of tenths of seconds with atomistic resolution. We use this method to study the growth of polyphosphate films from tricresyl phosphate (TCP) molecules on an iron substrate. Molecular adsorption, desorption, bond breaking/formation processes, and diffusion of iron ions through the film are simulated in the kMC stage and the film is relaxed during the MD stage. The kMC/MD method is approximately ten orders of magnitude faster than equivalent reactive force field (ReaxFF MD) simulations. The simulated film growth rate and topology agree well with experimental results and the chemical structure of the film is consistent with previous molecular dynamics simulations of iron polyphosphates. The newly-developed hybrid kMC/MD methodology can be adopted to yield important insights into thin film growth for several potential applications, which are also discussed.

Keywords

Off-lattice kinetic Monte Carlo
Molecular Dynamics
Multiscale modeling
Thin-film growth
Lubricant additives
Tricresyl phosphate

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.