The effect of rare earth substitution on the magnetic properties of Ni0.5Zn0.5MxFe2-xO4 (M: rare earth)

Variation of the complex permeability with frequency of Ni1-xZnxFe2O4 (x = 0.5, 0.6 and 0.7) prepared by a combustion method has been measured over a wide range of frequency, up to 1.8 GHz. Zn content improves permeability but moves the onset of resonance to lower frequencies. The influence on some properties of samples prepared by the insertion of small amounts of Ruthenium, Yttrium and rare-earth cations into the Ni0.5Zn0.5MxFe2-xO4 ferrite has been also investigated. Relative losses and Curie temperature of all the samples have been measured. Ferrites substituted with Ru and Gd improve microwave behavior compared to non-substituted samples. (C) 2002 Elsevier Science B.V. All rights reserved.