Electrophoretic deposition of iron oxide nanoparticles to achieve thick nickel/iron oxide magnetic nanocomposite films

Abstract

For modern switching power supplies, current bulk magnetic materials, such as ferrites or magnetic metal alloys, cannot provide both low loss and high magnetic saturation to function with both high power density and high efficiency at high frequencies (10-100 MHz). Magnetic nanocomposites comprised of a ferrite and magnetic metal alloy provide the opportunity to achieve these desired magnetic properties, but previously investigated thin-film fabrication techniques have difficulty achieving multi-micrometer film thicknesses which are necessary to provide practical magnetic energy storage and power handling. Here, we present a versatile technique to fabricate thick magnetic nanocomposites via a two-step process, consisting of the electrophoretic deposition of an iron oxide nanoparticle phase into a mold on a substrate, followed by electro-infiltration of a nickel matrix. The deposited films are imaged via scanning electron microscopy and energy dispersive X-ray spectroscopy to identify the presence of iron and nickel, confirming the infiltration of the nickel between the iron oxide nanoparticles. A film thickness of ∼7 μm was measured via stylus profilometry. Further confirmation of successful composite formation is obtained with vibrating sample magnetometry, showing the saturation magnetization value of the composite (473 kA/m) falls between that of the iron oxide nanoparticles (280 kA/m) and the nickel matrix (555 kA/m). These results demonstrate the potential of electrophoretic deposition coupled with electro-infiltration to fabricate magnetic nanocomposite films.

0‐3 magnetic nanocomposites via EPD: Current status for power component fabrication and future directions

“…Previously, the EPD of magnetic oxide nanoparticles was not utilized to fabricate magnetic nanocomposites, due to a focus on monolayer film formation, and the fact that these were often not able to achieve film thicknesses above F I G U R E 2 Schematic of electrophoretic deposition (EPD) with a graphite block as the positive electrode and the substrate as the negative electrode, showing the electrophoresis of iron oxide nanoparticles (positively charged, here) toward the negatively charged electrode, depositing on the substrate, a silicon wafer sputtered with titanium (adhesion layer) and gold (surface layer). Reproduced from Mills et al 29 (CC-BY).…”

“…28 However, depositing iron oxide nanoparticles via EPD, which previously had not been extensively studied, and challenges of film adhesion are addressed in this work via EPD parameter optimization and substrate functionalization for film stability. 29,30 Next, the use of EI for infiltrating a magnetic material within the nanoparticle film with the subsequent crosssectional and magnetic characterization of the fabricated 0-3 nanocomposites with this novel method are presented, showing the cumulative fabrication process. EI, a method utilized by Wen et al 26 and Hayashi et al 31 utilizes a typical electroplating set-up to "infiltrate" the porous nanoparticle film with the electroplated metal of choice.…”

Advances in electrochemical detection methods for measuring contaminants of emerging concerns

“…Films with different characteristics, for example, thickness and homogeneity, can be formed by varying the electric field strength, solvent type, particle size, and the electrophoretic mobility. [122] This method has been used to deposit gold nanoparticles of different sizes onto ITO glass electrodes by applying 0.2-1.6 V. Nanoparticles of metal oxides and sulfides, such as copper, [123,124] iron, [125] cobalt, [126] zinc, [127] and titanium, [128] have been deposited under optimized conditions. Carbon-based materials such as graphene oxide, [129][130][131][132][133] graphene quantum dots, [134] carbon nanotubes, [135] and their composites were deposited using applied voltages ranging from 2 to 100 V, selected based on the charge and mobility of the materials.…”

Fabrication of PZT Thick Film by Electrophoretic Deposition on the Platinum Substrate

“…Electrophoretic deposition (EPD) is a promising method since it is low cost, fast and suitable for uniform coverage of complex geometries (Ma et al, 2003;Kalinina & Pikalova, 2019;Szklarska et al, 2020). It can be used to manufacture thick films and fiber-reinforced composites and nanostructured materials (Ng & Boccaccini, 2005;Mills et al, 2020;Mittal & Rhee, 2021;Rehman et al, 2021). EPD comprises of electrophoresis and deposition processes.…”