Magnetization reversal mechanism of chemically synthesized linear chains of α-Fe nanospheres

Abstract

We report upon synthesis of stable chains of magnetically aligned zero-valent α-Fe nanoparticles and investigation of their magnetization reversal mechanism. The magnetic hysteresis loops with magnetic field applied at various directions with respect to the nanoparticle chain are measured experimentally and reproduced numerically by precisely mimicking the sample geometry under finite element modeling. The magnetization reversal mechanism is visualized in all three dimensions (3Ds) using 3D simulation and visualization toolkits. The reversal is found to nucleate from the ends of the chains and progressed through curling and fanning modes, vortex nucleation, propagation and annihilation. A better quantitative agreement is observed for increased number of nanoparticles and parallel chains.