Title :
Domain wall resonance and its effect on losses in ferrites
Author :
Gradzki, Pawel M. ; Lee, Fred C.
Author_Institution :
Bradley Dept. of Electr. Eng., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA
Abstract :
The core loss characterization in ferrites under strong magnetic fields is studied for high-frequency power converter applications. The measurements show strong dependence of core loss on the magnitude of DC or AC magnetic fields. An induced anisotropy field, due to material composition or applied bias field, causes multiple peaks in permeability and core loss characteristics at certain frequencies due to domain wall resonances. The characteristics of certain nickel-zinc ferrites, such as 4C4, degrade permanently after they are exposed to a strong magnetic field, which results in an irreversible alteration of the local magnetic anisotropies and their corresponding domain wall resonances
Keywords :
ferrites; induced anisotropy (magnetic); magnetic cores; magnetic domain walls; magnetic leakage; magnetic permeability; power convertors; 4C4; AC magnetic fields; DC magnetic fields; Ni1-xZnxFe2O4; applied bias field; core loss; domain wall resonances; ferrites; high-frequency power converter; induced anisotropy field; losses; magnetic fields; nickel-zinc ferrites; permeability characteristics; Anisotropic magnetoresistance; Composite materials; Core loss; Ferrites; Loss measurement; Magnetic domain walls; Magnetic field measurement; Magnetic materials; Magnetic resonance; Permeability;
Conference_Titel :
Power Electronics Specialists Conference, 1991. PESC '91 Record., 22nd Annual IEEE
Conference_Location :
Cambridge, MA
Print_ISBN :
0-7803-0090-4
DOI :
10.1109/PESC.1991.162741
