Radio frequency heating of magnetic perovskite nanoparticles in solution for biomedical applications

Abstract

Magnetic nanoparticles (MNPs) are widely used in many different sectors especially within biological applications for heat generation or as contrast agents in magnetic resonant imaging. Our research concentrates on the magnetic susceptibility of MNPs and the effect on heat generation applications for use in biomedical applications as an alternative to invasive treatments such as chemotherapy. In this thesis we have studied the response of clusters and chains of magnetic nanoparticles in solution. In particular we have focused on chains of MNPs that form through the spontaneous agglomeration of clusters. We are interested in magnetic response of MNP chains and how the response of the MNPs change with increasing chain lengths and different particle sizes. To understand the response of MNPs we have implemented the stochastic-Landau-Liftshitz-Gilbert equation in the high friction limit to study their rotational magnetic response. We have modelled chains of dipolarly coupled MNPs up to twenty particles long and two different sizes of MNP (10 nm and 20 nm radius particles). We have found that chains of MNPs show at least two resonant frequency modes and a marked deviation from the response predicted by a simple rigid body model. In particular the high frequency rotational response of the chain shows a crossover between the rigid body coherent response to an incoherent independent particle response. Implications to the specific absorption rate and heating capabilities of these chain are finally discussed. The code implemented during this doctoral project has been made available from https://mangocode.gitlab.io.

Date of Award	Jul 2020
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Northern Ireland Department for the Economy
Supervisor	Danai Poulidi (Supervisor) & Lorenzo Stella (Supervisor)