Abstract
Heat transport mediated by near-field interaction in particulate system (e.g. chain of particles) is one of the research focuses in thermal transport in micro-nanoscale. Near field radiative heat transfer (NFRHT) characteristics of metallic nanoparticle chains (separation distance between neighboring particles is h) are analyzed by means of both coupled electric-magnetic dipole approximation and quadrupole approximation. Thermal conductance (G) between the central particle and other particle with different separation gaps (Δx) is calculated at both 300K and 1200K. Corrected polarizability is used to take quadrupole effect into consideration when calculating the NFRHT in extreme near field where dipole approximation ceases to be valid. Temperature distributions along several different chains of particles due to NFRHT are also predicted. Results show that, according to the asymptotic behavior of distribution of G along metallic chains similar as that observed in SiC chains, heat super-diffusion is demonstrated at both 300K and 1200K in metallic nanoparticle chains. At 300K, the contribution of quadrupole results in that thermal conductance responses to h in different way in metallic and dielectric particle chains. Temperature distribution and heat flow are the two key parameters used to characterize the heat transport in chains of particles. Ag particles in SiC chain act as barriers during the radiative heat transport process. Heat super-diffusion, as well as some other characteristics of NFRHT, observed in metallic nanoparticle chains may help for insight of heat transport in particulate system and new design of device in micro-nanoscale.
The Thermal Discrete Dipole Approximation (T-DDA) for near-field radiative heat transfer simulations in three-dimensional arbitrary geometries
