Studies of static and high-frequency magnetic properties for M-type ferrite BaFe 12-2xCo xZr xO 19

Abstract

Static and high-frequency magnetic properties have been studied for BaFe 12-2xCo xZr xO 19 with x=0-1.2. The x-ray diffraction and M-H curves of aligned samples show that Co-Zr substitution can modify the anisotropy of BaFe 12-2xCo xZr xO 19. BaFe 12-2xCo xZr xO 19 with x≤0.6 has an easy c-axis anisotropy and the anisotropy fields rapidly decrease with Co-Zr substitutions. The sample of x=1.2 has an easy c-plane anisotropy with H a=5kOe. The saturation magnetizations of BaFe 12-2xCo xZr xO 19 are almost constant at x≤0.4 and decrease with higher substitutions. The coercivity decreases rapidly from 2400 Oe for the sample of x=0 to about 10 Oe for the sample of x=0.8. The natural resonance frequencies are observed at 4.5 and 5.0 GHz for the samples of x=0.8 and x=1.2, respectively. Based on microwave measurement and theoretical estimations on reflectivity, BaFe 12-2xCo xZr xO 19 may be a good candidate for electromagnetic compatibility and other practical applications at high frequency.© 2002 American Institute of Physics.