An atomistic description of alloys and core shells nanoparticles

TL;DR

This study uses an extended discrete interaction model to analyze how surface plasmon resonance in alloy and core-shell nanoparticles made of silver and gold depends on composition, size, and geometry, revealing mostly predictable behavior with minimal atomic arrangement effects.

Contribution

It introduces a detailed statistical and physical analysis of surface plasmon resonance in alloy and core-shell nanoparticles, highlighting the minimal influence of atomic distribution and the non-linear polarizability behavior.

Findings

Surface plasmon resonance largely follows Vegard's law regardless of nanoparticle geometry.

Polarizability exhibits highly non-linear behavior with composition and size.

Dependence on atomic arrangement diminishes with increasing nanoparticle size.

Abstract

Using the extended discrete interaction model we investigate the tuneabilty of surface plasmon resonance in alloys and core-shell nanoparticles made from silver and gold. We show that the surface plasmon resonance of these alloys and core-shell particles to a large extent follow Vegard's law irrespective of the geometry of the nanoparticle. We show the evolution of the polarizability with size and demonstrate the highly non-linear behaviour of the polarizability with the ratio of the constituents and geometry in alloys and core-shell nanoparticles, with the exception for nanorod alloys. A thorough statistical investigation reveals that there is only a small dependence of the surface plasmon resonance on atomic arrangement and exact distribution in a nanoparticle and that the standard deviation decrease rapidly with the size of the nanoparticles. The physical reasoning for the random distribution algorithm for alloys in discrete interaction models is explained in details and verified by the statistical analysis.