Optimum Size of Nanorods for Heating Application

TL;DR

This paper theoretically analyzes the optimal size of rod-shaped magnetic nanoparticles for heating applications, revealing conditions for maximum efficiency and the impact of size dispersion on heating performance.

Contribution

It introduces a theoretical framework to determine the optimal dimensions of nanorods considering size distribution effects for heating applications.

Findings

Rod-shaped particles can match spherical particles in power generation when optimally sized.

Size dispersion enhances heating efficiency for rod-shaped particles due to broader power density distribution.

Radius dispersion impacts power loss more significantly than length dispersion in nanorods.

Abstract

Magnetic nanoparticles (MNP's) have become increasingly important in heating applications such as hyperthermia treatment of cancer due to their ability to release heat when a remote external alternating magnetic field is applied. It has been shown that the heating capability of such particles varies significantly with the size of particles used. In this paper, we theoretically evaluate the heating capability of rod-shaped MNP's and identify conditions under which these particles display highest efficiency. For optimally sized monodisperse particles, the power generated by rod-shaped particles is found to be equal to that generated by spherical particles. However, for particles which have a dispersion in size, rod-shaped particles are found to be more effective in heating as a result of the greater spread in the power density distribution curve. Additionally, for rod-shaped particles, a dispersion in the radius of the particle contributes more to the reduction in loss power when compared to a dispersion in the length. We further identify the optimum size, i.e the radius and length of nanorods, given a bi-variate log-normal distribution of particle size in two dimensions.