Abstract
We have developed new low loss ferrites with a magnetic loss of less than 100kW/m3 at MHz, 50mT and 80°C, which was 1/5 times of that of coventional low loss ferrites. These new low loss ferrites were obtained by the following principle and technology:
(1) A simple method was applied to separate the magnetic loss into a hysteresis loss, an eddy current loss and a residual loss.
(2) Hysteresis loss and eddy current loss were simultaneously reduced by the segregation of additives highly concentrated at grain boundaries.
(3) Residual loss, which is probably associated with domain wall resonance, was reduced to almost zero by controlling permeability.
