Interaction effects enhancing magnetic particle detection based on magneto-relaxometry

Abstract

We investigated the effects of dipolar interactions on the long-time magnetization decay M(t) in clusters of magnetic nanoparticles. Applying the Néel-Arrhenius thermal activation picture shows that M(t) generally follows stretched exponential behavior, dependent not only on the dipolar interaction strength, geometry of particle arrangement within clusters, but also on the field history applied during the initialization. As demonstrated, combining these factors could serve to enhance the degree of resolution in magnetic particle detection based on magneto-relaxometry.