Permalloy nanowires/graphene oxide composite with enhanced conductive properties

Abstract

carbon-metal-based composites arise as advanced materials in the frontiers with nanotechnology, since the properties inherent to each component are multiplexed into a new material with potential applications. in this work, a novel composite consisting of randomly oriented permalloy nanowires (py nWs) intercalated among the sheets of multi-layered graphene oxide (Go) was performed. py nWs were synthesized by electrodeposition inside mesoporous alumina templates, while Go sheets were separated by means of sonication. Sequential deposition steps of Py NWs and GO flakes allowed to reach a reproducible and stable graphene oxide-based magnetic assembly. Microscopic and spectroscopic results indicate that py nWs are anchored on the surface as well as around the edges of the multi-layered Go, promoted by the presence of chemical groups, while magnetic characterization affords additional support to our hypothesis regarding the parallel orientation of the Py NWs with respect to the GO film, and also hints the parallel stacking of GO sheets with respect to the substrate. the most striking result remains on the electrochemical performance achieved by the composite that evidences an enhanced conductive behaviour compared to a standard electrode. Such effect provides an approach to the development of permalloy nanowires/graphene oxide-based electrodes as attractive candidates for molecular sensing devices. Composite materials arise as versatile candidates that could be designed to satisfy diverse technological applications due to their multifunctional behaviour. Since composites are obtained by combining two or more materials that have different attributes, such assembly provides to the composite of unique properties. In fact, several examples exist that have demonstrated the industrial development behind their production, being the concrete a well-known composite, where its strength under compression is improved by adding metal rods, wires, mesh or cables in order to create reinforced concrete. Most of the current composites have been made by carbon allotropes 1, 2. In particular, when graphene is combined with the metallic copper, a new material around 500 times stronger than copper is achieved 3. Likewise, composites constituted by graphene and nickel yield a strength larger than 180 times of nickel 4. A soft Ni-rich ferromagnet 5, 6 , that is widely employed as a magnetic core material in diverse technological applications, such as magnetic recording heads 7-9 , microinductors and magnetoresistive random access memories (MRAM) 10, 11 , is the so called permalloy (Py), an alloy with about 20% iron and 80% nickel content. On the one hand, bulk Py exhibits large magnetic permeability, enhanced sensitivity in sensing devices 12 , as well as low coercivity and remanence, of interest in magnetic shielding 13. In addition, it is a material with nearly zero magnetostriction, an attribute that promotes an easier integration in different devices 13. Besides, the high Ni content provides an excellent corrosion resistance to the alloy...

Tunable Magnetic Properties of Interconnected Permalloy Nanowire Networks

“…The unique combination of high magnetic permeability, low coercivity, and excellent thermal stability makes permalloy an ideal candidate for various technological advancements, including magnetic sensors, magnetic random-access memory (MRAM), and spintronic devices [ 2 , 3 ]. In recent years, the exploration of permalloy at the nanoscale has gained prominence, with a particular focus on the synthesis, characterization, and manipulation of permalloy nanowires [ 4 , 5 ]. These nanoscale structures exhibit intriguing magnetic behaviors and offer great potential for further advancements in nanoelectronics and magnetic nanodevices.…”

Electrodeposited Ni-Fe onto Glassy Carbon for the Detection of Methylene Blue

“…20,21 At the metal-carbon interface, d(metal)-π(carbon) orbital coupling can change the density of states, and spin population, and perhaps influence adsorption of MB. Jaimes et al 22 recently showed that permalloy, an alloy of 80% Ni and 20% Fe, in the form of nanowires integrated with graphene greatly improved the conductivity. For these reasons, a Ni-Fe alloy, near the permalloy composition, was selected as the metal material.…”