Frequency Dependence of Complex Permeability of Polycrystalline Ferrites Based on the Realities of Microstructure
International Conference on Materials and Applications for Sensors and Transducers (IC-MAST 2012): Book of Abstracts 2012
Jānis Jankovskis, Nikolajs Ponomarenko, Deniss Stepins

Analytic presentation of frequency dependence of complex initial permeability (CIP) of polycrystalline ferrites (PF) within their most typical – large amplitude dispersion region at radiofrequencies still involves considerable problems. The difficulties arise from the fact that the dispersion of CIP manifests itself within a broad range of frequency and yet exhibits several attributes of resonance. Now the best suited to experiments is the presentation of CIP by formal combination of two relationships – simple relaxation and resonance ones. But such a presentation of CIP is highly implicit and limited. More appropriate presentation there is worked out in fact on the basis of starting fundamental idea [A. Fairweather, at all. Rep. Prog. Phys., 1952, vol.15, p. 160] that “in a material which is not magnetically homogeneous, it is plausible that the resonant frequency is, in general, different in different elementary volumes”. This conception has been brought up to analytic relationship for CIP by principle assumption that the elementary volumes are that ones formed by polycrystal grains, that the resonating objects are domain walls within grains, that the magnetization process in elementary volumes is resembling the ones observed for variety of samples with different average grain size. Statistical averaging over the aggregate of grains – PF sample gives, e.g., the log-normal type relation for the absorption component of CIP. The results gained may found wide use.


Keywords
complex initial permeability, polycrystalline ferrites, polycrystal grains

Jankovskis, J., Ponomarenko, N., Stepins, D. Frequency Dependence of Complex Permeability of Polycrystalline Ferrites Based on the Realities of Microstructure. In: International Conference on Materials and Applications for Sensors and Transducers (IC-MAST 2012): Book of Abstracts, Hungary, Budapest, 24-28 May, 2012. Athens: National Technical University of Athens, 2012, pp.136-136.

Publication language
English (en)
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