J. Phys. IV France 07 (1997) C1-195-C1-196
On the Mechanism of the Initial Permeability in MgMnZn-FerriteM. Kolenbrander1 and P.J. van der Zaag2
1 Philips Components, Central Innovation Magnetic Products, BE-2, P.O. Box 218, 5600 Eindhoven, The Netherlands
2 Philips Research Laboratories, Prof. Holstlaan 4, 5656 Eindhoven, The Netherlands
The magnetic permeability and the thickness of the so-called "non"-magnetic grain boundary were studied for a MgMnZn-ferrite with composition Mg0.8Zn0.2Mn0.1Fe1.85O3.925. For the mono-domain situation the grain size dependence of the effective initial permeability is well described by the nonmagnetic grain boundary model. A gradua1 increase of permeability with grain size around the transition from mono- to two-domain indicates that the permeability is predominantly rotational in origin. The intrinsic initial permeability and the "non"-magnetic grain boundary width were obtained from a fit of permeability versus grain size at different temperatures. It is found that the grain boundary thickness decreases with temperature. This suggests that the grain boundary is hard magnetic rather than nonmagnetic.
© EDP Sciences 1997