The effects of Nb2O5 and TiO2 on electrical and magnetic properties of Mn-Zn ferrites

Mn-Zn ferrites among iron oxide magnetic materials are widely used for high frequency magnetic core materials because they have low power loss and high initial permeability up to several MHz range. In this paper, the small amount of Nb2O5 and TiO2 were added to the Mn-Zn ferrites to study their effects on electrical and magnetic properties of the Mn-Zn ferrites. The amount of Nb2O5 and TiO2 was in the range of 0 -0.02 wt% and 0-0.6 wt% respectively. The effects of additives were studied in view of change in core loss, maximum flux density, specific resistivity, inductance and permeability. Adding both TiO2 (0.6wt%) and Nb2O5 (0.01 wt %), the core loss was lowest. It was decreased to 50% at 500 kHz. In this case, the maximum flux density was depressed by only 2%. This means that the additives could drastically decrease the minimum core loss with penalty of a little decrease in magnetic flux density. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.