On Thermal Vacuum Radiation of Nanoparticles and Their Ensembles

TL;DR

This study numerically investigates the thermal radiation of nanoparticle ensembles in vacuum, revealing oscillating emittance due to interparticle interactions and potential applications as heat sources or insulators.

Contribution

It introduces a fluctuation-electromagnetic theory-based analysis of nanoparticle ensembles' thermal radiation, highlighting effects of particle size, spacing, and material.

Findings

Ensembles can be more intense radiators than solid bodies of same surface area.

Neighboring particles can cause oscillations in radiance depending on parameters.

Silica particles can serve as effective thermal insulators due to screening effects.

Abstract

Radiant emittance of dimers and ensembles of particles consisting of gold, graphite and silica glass nanoparticles in vacuum is studied numerically based on the fluctuation-electromagnetic theory. The presence of neighboring particles of the same temperature causes an oscillating character of radiant emittance (per one particle) depending on the particle size, interparticle distance and temperature. We conclude that an ensemble of particles could be a much more intense source of thermal radiation than an equivalent solid body with the same outer surface area. Alternatively, when the neighboring particles create a significant screening effect (silica), an ensemble of particles could be a very good heat protector.