Formation of magnetic nanocolumns during vapor phase deposition of a metal-polymer nanocomposite: experiments and kinetic Monte Carlo simulations

TL;DR

This study combines experiments and kinetic Monte Carlo simulations to understand the formation of nanocolumns in metal-polymer nanocomposites during vapor deposition, revealing key conditions for their self-organization.

Contribution

It introduces a new kinetic Monte Carlo model incorporating nanoscale melting point depression and critical size for solidification, advancing understanding of nanocolumn formation.

Findings

Nanocolumns form under specific vapor deposition conditions.

Simulations align quantitatively with experimental results.

Depression of melting point influences nanostructure morphology.

Abstract

Metal-polymer nanocomposites have been investigated extensively during the last years due to their interesting functional applications. They are often produced by vapor phase deposition which generally leads to the self-organized formation of spherical metallic nanoparticles in the organic matrix, while nanocolumns are only obtained under very specific conditions. Experiments\cite{Grev+06} have shown that co-evaporation of the metallic and organic components in a simple single-step process can give rise to the formation of ultrahigh-density Fe-Ni-Co nanocolumnar structures embedded in a fluoropolymer matrix. Here we present a kinetic Monte Carlo approach which is based on an new model involving the depression of the melting point on the nanoscale and a critical nanoparticle size required for solidification. In addition we present new experimental results down to a deposition temperature of \cel{-70} and also report the magnetic properties. The simulations provide a detailed understanding of the transition from spherical cluster growth to formation of elongated structures and are in quantitative agreement with the experiments.