Magnetization reversals in magnetosome linear-chain assemblies extracted from magnetotactic bacteria: an experimental and micromagnetic simulation study

Abstract

Magnetotactic bacteria have attracted considerable attention due to their ability to synthesize biocompatible magnetic nanoparticles. In this study, we explore the potential of these nanoparticles for fabricating linear-chain arrays of magnetosomes and investigate the magnetization reversal process of these assemblies. By varying the concentrations of magnetosome solutions and the strength of externally applied magnetic fields, we investigate the effects of magnetostatic interaction between individual linear chains on the magnetization reversal process. Our experimental results combined with delicate micromagnetic simulations demonstrate that the magnetostatic interaction between adjacent linear chains is crucial in the nucleation of reversed magnetization, as well as its subsequent propagation along each chain through particle-by-particle switching. These findings provide insights into the magnetization reversal process of magnetic nanoparticle linear-chain assemblies and offer an alternative route for the fabrication of the biocompatible Fe₃O₄ nanoparticle assemblies extracted from the magnetotactic bacteria.