Anomalous diffusion mediated by atom deposition into a porous substrate

TL;DR

This paper investigates how constant atom deposition into a porous medium creates a dense overlayer that influences atomic diffusion, modeled through a generalized diffusion equation with a dynamic diffusion coefficient.

Contribution

It introduces a novel model generalizing the porous diffusion equation to include a time-dependent diffusion coefficient influenced by atom deposition.

Findings

Formation of a dense overlayer during atom deposition

Overlayer acts as a dynamic control on diffusion

Generalized diffusion model with nonlinear time rescaling

Abstract

Constant flux atom deposition into a porous medium is shown to generate a dense overlayer and a diffusion profile. Scaling analysis shows that the overlayer acts as a dynamic control for atomic diffusion in the porous substrate. This is modeled by generalizing the porous diffusion equation with a time-dependent diffusion coefficient equivalent to a nonlinear rescaling of time