Abstract
Toroidal-shaped high-density Fe nanoparticle assemblies (FNAs) were fabricated by molding different sized Fe nanoparticles (NPs), and the effect of the magnetic behavior of the FNAs on the core loss and the magnetic susceptibility was investigated. An FNA with 4.3 nm diameter Fe NPs exhibits superparamagnetism at room temperature while an FNA with 6.4 nm diameter Fe NPs doesn’t exhibit superparamagnetism at room temperature. AC magnetization curves at 1, 10 and 100 kHz were measured to evaluate the core loss of the toroidal-shaped FNAs. Both FNAs exhibited no significant eddy current loss, which suggests that surfactants on the NP surface effectively act to electrically insulate the NPs, and the NPs are not sintered together when the FNAs are molded. The AC magnetization curves had no hysteresis for the FNA with 4.3 nm diameter Fe NPs, i.e., the core loss was minimal for the superparamagnetic FNA. The magnetic susceptibility of the superparamagnetic FNA with 4.3 nm Fe NPs was 12 times higher than that estimated from Langevin theory due to the effect of strong magnetic dipole interaction. These results suggest that the superparamagnetic FNA has potential as a magnetic core material that exhibits low core loss and high magnetic susceptibility, even at high frequency.
Highlights
Soft magnetic materials are widely used as magnetic cores for transformers, motors and generators
We have proposed Fe nanoparticle assembly (FNA) as a new high frequency magnetic core material.[7]
The superparamagnetic FNA has only small losses from both hysteresis and eddy current losses, and is expected to be a low core loss material that can be used in higher frequency ranges than conventional core materials
Summary
Soft magnetic materials are widely used as magnetic cores for transformers, motors and generators. Core loss and magnetic susceptibility of superparamagnetic Fe nanoparticle assembly Masane Kin,1,a Hiroaki Kura,[1] and Tomoyuki Ogawa2 1Research Laboratories, DENSO CORPORATION, 500-1, Minamiyama, Komenoki-cho, Nisshin, Aichi 470-0111, Japan 2Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, 6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan (Received 12 October 2016; accepted 28 November 2016; published online 8 December 2016) FNAs are expected to be low eddy current loss materials because the FNA is composed of magnetic nanoparticles (NPs) and surfactants as an electrical insulator.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
