High Frequency Characteristic of Elements Substituted Hexagonal Ferrites
The initial permeability μ' (at 0.1 GHz) of Ba3Co2R0.1Fe23.9O41 (x=0.1, R= Gd, Dy, Ho, Yb) samples is higher than that of the Co2Z ferrite without substitution. In particular, μ' of Gd3+ substituted Z-type ferrite sample (x=0.1) is the highest of all samples. The substituted sample of Ba3Co2TixZnxFe24-2xO41 with x= 0.85 has a maximumμ' of 24, which is twice as large as that of the non-substituted sample with x=0. Ba3Co2-2x LixFe24+xO41(x=0-1.0) are also prepared. The sample with x=0 showsμ'of 8 at 50MHz. The maximumμ' is 24.5 at x=0.3. An apparent magnetic anisotropy constant K*, calculated by using HA* and MS, decreases. Therefore, the decrease of the magnetic anisotropy contributes to the increase of μ'.
Tadashi Takenaka, Hajime Haneda, Kazumi Kato, Masasuke Takata and Kazuo Shinozaki
N. Hiratsuka et al., "High Frequency Characteristic of Elements Substituted Hexagonal Ferrites", Key Engineering Materials, Vols. 421-422, pp. 541-545, 2010