Interface coupling-induced enhancement of magnetoimpedance effect in heterogeneous nanobrush by adjusting textures of Co nanowires

Abstract

Interface coupling-induced and interface coupling-enhanced magnetoimpedance (MI) effect in heterogeneous nanobrush has been investigated. The nanobrush is composed of Fe25Ni75 nanofilm and textured hexagonal close-packed cobalt nanowire array, respectively fabricated by RF magnetron sputtering and electrochemical deposition. The design of this structure is based on the vortex distribution of magnetic moments in thin film, which can be induced by the exchange coupling effect at the interfaces of the nanobrush. The texture of nanowires plays an important role in the MI effect of the nanobrush, which is regulated by controlling the pH values and temperatures of the deposition process. The ‘parallel’ and ‘perpendicular’ coupling models were used to explain the different MI results of the nanobrush with cobalt nanowires, which have (100) and (002) textures, respectively. The optimized MI effect of the nanobrush brought by (100) nanowires can be magnified by 300% with more than 80%/Oe magnetic sensitivity at a low frequency, which has great application potentials in low-frequency MI sensors.