Hysteresis in a magnetic bead and its applications

TL;DR

This paper investigates hysteresis behavior in superparamagnetic beads using mean-field theory, highlighting their potential for controlled heating in therapeutic applications and introducing the concept of return point memory for localized heating.

Contribution

It presents a theoretical model of hysteresis in magnetic beads considering dipolar interactions and explores applications in heat dissipation control and localized heating.

Findings

Hysteresis can be manipulated by adjusting field frequency and amplitude.

Return point memory enables gradual, localized heating.

Theoretical framework aligns with potential therapeutic uses.

Abstract

We study hysteresis in a micron-sized bead: a non-magnetic matrix embedded with super- paramagnetic nanoparticles. These hold tremendous promise in therapeutic applications as heat generating machines. The theoretical formulation uses a mean-field theory to account for dipolar interactions between the supermoments. The study enables manipulation of heat dissipation by a compatible selection of commercially available beads and the frequency f and amplitude ho of the applied oscillating field in the labortory. We also introduce the possibility of utilizing return point memory for gradual heating of a local region.