Magnetic field induced one-dimensional nano/micro structures growth on the surface of iron oxide thin film

Abstract

The influence of external magnetic field on the morphology of alpha-Fe2O3 thin film formed at liquid-vapor interface has been investigated. Application of magnetic field during the growth of film resulted in the magnetic moment ordering of constituent nanoparticles. Thus formed alpha-Fe2O3 thin film was transferred to a glass substrate, which upon annealing converted into one dimensional (1D) nanostructured thin film due to the oriented attachment of magnetically ordered nanoparticles. The effect of dopants viz. Ni2+ and Co2+ on the directional growth, and magnetic properties of nanostructures has also been investigated. The Ni2+ and Co2+ doped alpha-Fe2O3 1D nanostructured thin films show superparamagnetic and ferromagnetic behavior, respectively, whereas undoped alpha-Fe2O3 film exhibits superparamagnetism. From the room temperature magnetization measurements of films, it is found that the magnetization depends upon the morphology and magneto-crystalline anisotropy attributes of the film nanostructures. (C) 2015 Elsevier B.V. All rights reserved.