Abstract
Permalloy (Ni/sub 47/Fe/sub 53/) microspheres of 4 and 8 /spl mu/m in average diameter were encapsulated with Ni-Zn ferrite by ultrasound enhanced ferrite plating from an aqueous solution at 80/spl deg/C at pH=6-9. The ferrite-encapsulated microspheres were compacted to toroidal cores, on which complex permeability (/spl mu/=/spl mu/'-j/spl mu/'') was measured. The natural ferromagnetic resonance frequency f/sub r/ (criterion for usable frequency), and /spl mu/' of the cores exceeded Snoek's limit for Ni-Zn ferrite bulk by one order of magnitude. The cores exhibited one-turn-coil impedance exceeding 40 /spl Omega/ at 1-3 GHz, suggesting that they will be applied to gigahertz electromagnetic compatibility bead inductors to suppress electromagnetic noises. In addition, the cores will be applied to low-loss inductors operated at tens of megahertz, since they have Q=/spl mu/'//spl mu/''>100 up to 45 MHz when the microspheres were plated at pH=6.
Sign-in/Register to access full text options 
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.
