Magnetization reversal in chemically synthesized chains of permalloy nanospheres

Abstract

Controlled magnetic interactions in magnetic nanoparticles are a fundamental concern to the future development of nanometer-sized “magnonic” device applications. Here, we report the magnetization reversal mechanism in one-dimensional chain-like structures made of permalloy (Ni80Fe20) magnetic nanoparticles of about 200 nm diameters. Well-aligned and uniform permalloy nanochains have been synthesized using a chemical synthesis method under applied magnetic fields. The morphological, microstructural and compositional studies confirm the linear distribution of stoichiometric permalloy nanoparticles with spherical shape along the applied magnetic field to form chain-like structure. Magnetic measurements also demonstrate that the magnetization reversal is mainly attributed to the spherical vortices and shape anisotropy of the chains and typical hard and easy-axis magnetic hysteresis loops. Micromagnetic simulations (OOMMF) are performed to comprehend the experimental results and to make a correlation with the magnetization reversal mechanism in permalloy nanoparticle chains.