A correlation between microstructure and frequency dependent magnetic properties of Mn-Zn ferrites was established using the inductance spectroscopy method. Several atmosphere conditions and dwell times and temperatures were used during sintering to obtain a variety of microstructures in samples of different compositions. Results show that initial permeability (μi) strongly depends on the atmosphere composition during sintering, it increases, while relaxation frequency (fr) slightly decreases as oxygen content decreases. On the other hand, dwell times longer than three hours led to a slight decrease in permeability (μ) and an increase in fr. For the compositions prepared, a systematic decrease in μ was observed as zinc content decreases, regardless of the sintering conditions used. For each composition a maximum in μ was obtained for the same sintering conditions, which also correspond to the highest density values
Published in:
Magnetics, IEEE Transactions on
(Volume:37
,
Issue:
4
)
Date of Publication: Jul 2001