Estimation of the superhigh-frequency magnetic permeability of alsifer from the measured permeability of composites

A Technique to Retrieve High-Frequency Permeability of Metals From Constitutive Parameters of Composites With Metal Inclusions of Arbitrary Shape, Estimate of the Microwave Permeability of Nickel

“…The properties of the metal powder and that of bulk metal may differ significantly. The specific resistance for carbonyl nickel fitted in this work (8 × 10 −5 Ω × m) accounting for skinning is an order higher than the handbook data (6.8 × 10 −6 Ω × m) for Ni; the estimated static permeability (∼ 10) is also significantly lower than the static permeability (300-600) reported for bulk Ni [7].…”

“…The skinning contribution may be accounted for by using handbook data for the nickel conductivity (1.47×10 7 Ω −1 m −1 ) [7] and the inclusion thickness d is estimated microscopically; it is therefore possible to calculate the intrinsic permeability of the metal comprising the inclusion μ metal (f ) excluding skinning.…”

“…may be treated [3,4] together with permeability. The measurement of several transport properties of composite samples is necessary because realistic mixing models (the general models that account for inclusion shape and interaction) have several unknown parameters that cannot be determined accurately treating the measured permeability only [5][6][7].…”

“…The permittivity measurements with Ni are more complicated than measurements of composites with iron or sendust powders [5][6][7], as Ni powders are electrically conductive because of oxide-free particle surface. A thin (less than 2% of inclusion diameter) oxide layer inherent to iron-based alloys suppresses the electric contact between the neighboring particles and decreases the effective permittivity of inclusion down to ∼ 10 3 [18]; the inclusion in a shell is conventionally considered as a homogeneous substance.…”

“…The Sihvola mixing model [20] is modified and applied here to treat the constitutive parameters determined experimentally. In contrast to the previous publications [5][6][7], the applied mixing model is more general than the Odelevskiy and Bruggeman models; the Sihvola mixing model describes a range of mixture structures (see Section 3) using the same number of fitted parameters as in publications [5][6][7] but accounts for the finite linewidth of the geometric spectral function [9,21,22]. This linewidth is a function of inclusion shape, filling factor and of composite structure.…”