Microwave permeability of Co2Z composites -: art. no. 013905
Microwave permeability of Co2Z composites -: art. no. 013905
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DOI：
10.1063/1.1827911
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发表时间：
2005-01-01
影响因子：
3.2
通讯作者：
Koledintseva, MY
中科院分区：
文献类型：
--
作者：
Rozanov, KN;Li, ZW;Koledintseva, MY
测量了Co(2)Z钡铁氧体复合样品的微波介电常数和磁导率随频率和体积分数的变化关系。测定了块体铁氧体的静磁性能。这使得斯诺克定律[J.L.Snoek，Physica 14,204(1948)]可以通过比较微波和静磁的斯诺克常数来验证。对六方铁氧体的斯诺克定律的修正是由Acher[Phys.B版本62,11324(2000年)]也得到了验证。微波测量得到的Acher常数与块体铁氧体的静磁特性计算值基本一致，但微波和静磁Snoek常数不一致。这可能是由于铁素体夹杂物的退磁因素的影响，而斯诺克定律和阿彻定律的推导中没有考虑这些因素。测得的复合材料的频率相关磁导率满足洛伦兹色散定律，并与Maxwell Garnett近似[J.C.Maxwell Garnett，Philos]一致。翻译过来的。R.Soc.伦敦203,385(1904)]。根据洛伦兹色散定律和麦克斯韦石榴石混合规则的理论分析，Snoek常数和Acher常数都必须是体积分数的线性函数，而与微波值和静磁值是否一致无关。相反，实验测量表明，这两个常数都随着体积分数的增加而稳定地减小。讨论了复合材料中有效介质对铁氧体颗粒固有磁导率的影响。(C)2005年美国物理研究所。
The microwave permittivity and permeability of Co(2)Z barium ferrite composite samples are measured as functions of frequency and volume fraction of the ferrite. Magnetostatic properties of the bulk ferrite are determined. This allows Snoek's law [J. L. Snoek, Physica 14, 204 (1948)] to be verified by comparing the microwave and magnetostatic Snoek's constants. The modification of Snoek's law for hexagonal ferrites suggested recently by Acher [Phys. Rev. B 62, 11324 (2000)] is also verified. Acher's constant is found from microwave measurements to agree with the value calculated from the magnetostatic properties of bulk ferrite, but microwave and magnetostatic Snoek's constant do not agree. This may be attributed to the effect due to demagnetizing factors of ferrite inclusions that are not considered in the derivation of Snoek's and Acher's laws. The measured frequency-dependent permeability of composites satisfies the Lorentzian dispersion law and is consistent with the Maxwell Garnett approximation [J. C. Maxwell Garnett, Philos. Trans. R. Soc. London 203, 385 (1904)]. According to the theoretical analysis based on the Lorentzian dispersion law and the Maxwell Garnet mixing rule, both Snoek's and Acher's constants must be linear functions of the volume fraction, independent of whether microwave values of the constants are in agreement with the magnetostatic values. In contrast, the experimental measurements reveal a steady decrease of both constants with the volume fraction. The disagreement is discussed in terms of the influence of effective medium in composite on the inherent permeability of ferrite particles. (C) 2005 American Institute of Physics.