New views on the dissipation in soft magnetic ferrites

Neutron depolarization experiments show that below a certain grain size, po lycrystalline ferrites are composed of mono-domain grains. These mono-domai n ferrites exhibit low dissipation at MHz frequencies. This is attributed t o the absence of intragranular domain wall movement, i.e. a new microscopic origin for dissipation in ferrites has been identified. The implication of this finding for the domain wall contribution to hysteresis is discussed. (C) 1999 Elsevier Science B.V. All rights reserved.