Improvement on magnetic power loss of MnZn-ferrite materials by V2O5 and Nb2O5 co-doping

Simultaneous incorporation Of V2O5 and Nb2O5 dopants into low loss MnZn-ferrites markedly improves the power loss characteristics of the materials, provided no abnormal grain growth phenomenon was induced. The finer the grain size is, the smaller the power loss. The beneficial effect Of V2O5 and Nb2O5 co-doping is presumed to be the reduction on the eddy current loss for the MnZn-ferrite materials. However, the prime factor reducing the power loss in high frequency regime (3 MHz) is the suppression on residual power loss of the materials. The mechanism for the decrease in the residual power loss, in addition to the reduction on grain size (GS <2.27 mum) and the increase in grain boundary resistance (r(gb) > 70 Omega), is probably the increase in the uniformity of grain size distribution. (C) 2001 Elsevier Science Ltd. All rights reserved.