Frequency dependence of initial permeability and magnetic loss factor of [formula omitted] and [formula omitted] substituted Mg–Mn ferrites

Abstract

The frequency dependence of initial permeability (μi) and magnetic loss factor (tanδ), of the series Mg0.9Mn0.1InxFe2-xO4 and Mg0.9Mn0.1CryFe2-yO4 have been discussed in the present paper. The initial permeability for all the samples remains unchanged below 10kHz. For samples with x=0,0.1 and 0.3 the initial permeability is almost constant in the whole range of 10kHz–10MHz. For the sample x=0.5, the initial permeability remains constant up to 100kHz beyond which it falls. For Cr samples the initial permeability decreases with frequency and attain a certain minimum value for each sample at about 4MHz and beyond which it begins to raise. However the upper limit of the frequency available in the present study (10MHz) was too low to observe the resonance peaks in the prepared samples. The magnetic loss factor values lie in the range of 0.02–0.75 within the studied frequency range and the dispersion pattern could not be observed as upper limit frequency used in the present study was too low.