Study of microwave absorptions in M-hexaferrites for anti-radar applications*
Dubrunfaut, O.; Zouhdi, S.; Fourrier-Lamer, A.; Brando, E.; Vincent, H.; Dubrunfaut O.; LDIM EA 253/DSPT4/MENRT, Paris VI, 4 place Jussieu, 75252 Paris Cedex 05, France; Zouhdi S.; LDIM EA 253/DSPT4/MENRT, Paris VI, 4 place Jussieu, 75252 Paris Cedex 05, France; Fourrier-Lamer A.; LDIM EA 253/DSPT4/MENRT, Paris VI, 4 place Jussieu, 75252 Paris Cedex 05, France; Brando E.; LMGP (URA 1109 du CNRS), ENS de Physique de Grenoble, 38402 St Martin-d'Hères Cedex, France; Vincent H.; LMGP (URA 1109 du CNRS), ENS de Physique de Grenoble, 38402 St Martin-d'Hères Cedex, France
Журнал:
The European Physical Journal Applied Physics
Дата:
1999
Аннотация:
Microwave absorption of sintered M-type hexaferrites (BaFe<sub>12−2x </sub>Ru<sub> x </sub>Zn<sub> x </sub>O<sub>19</sub>) is investigated as a function of the substitution ratio x. The substitution with Ru and Zn has been shown to reduce the axial anisotropy of the BaM-hexaferrite which becomes in-plane for x ≈ 0.4. Large saturation magnetization and in-plane magnetic anisotropy allow to obtain high permeability values at microwave frequencies. To study the behavior of the ferrites at these frequencies, the complex constitutive parameters ε and μ (respectively permittivity and permeability) are simultaneously measured from 0.5 up to 18 GHz using a coaxial technique. Two absorption phenomena are observed: the ferrimagnetic resonance and the domain wall relaxation; the latter is studied with the Globus' model. Anti-radar applications are also mentioned.
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