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Amorphous ferromagnetic Ni(sub 45)Co(sub 25)Fe(sub 6)Si(sub 9)B(Sub 13)Mn(sub 2) wires obtained by melt extraction were examined by measuring its magnetoimpedance. The impedance was modeled by simultaneously solving Maxwell's equations and the Landau-Lifshitz equation of motion for the magnetization in a cylindrical magnetic conductor. The permeability of the wires was compared with the model with the dc magnetic field as implicit parameter. The method emphasized the region of ferromagnetic resonance and facilitated the investigation of the permeability locus.

The high frequency properties of amorphous and polycrystalline wires mounted as conductors in coaxial lines were investigated, by applying a static magnetic field along the wire axis. Peaks were observed in the real part of the impedance, moving to higher frequency with the strength of the static field, typical ferromagnetic resonance behaviour.

We have investigated the giant magnetoimpedance (GMI) effect in fibers of different soft magnetic materials and in Permalloy wires. The fibers have been tested in the radio frequency (rf) range, by measuring the voltage drops in different parts of the circuit. The wires have been tested in the ultra high frequency (uhf) range, by measuring the transmission coefficient [s.sub.21] of coaxial lines having as central conductor a HyMu80 wire. The two methods provided quite similar results showing a strong GMI effect for very different magnetic samples.

Ferromagnetic resonance (FMR) technique is employed to study the effect of magnetocrystalline anisotropy and dipolar interactions in Co nanowire arrays. The observed dependence of the effective anisotropy fields on the array geometry (wire length and diameter), interpreted in terms of the interwire dipolar interactions is found to be in agreement with theoretical predictions based on a micromagnetic model.

This paper deals with a numerical modelling technique based on finite elements method (FEM) in microwave frequency for computing the dielectric constant and loss factor of a homogeneous dielectric material by using conical-type coaxial probe. This sort of probe can be easily inserted into a wide range of biological tissue types and semi-rigid materials like rubber, some plastics, and organic materials (ex: dairy, butter, etc. for measuring moisture content). Where his feature is considered to be very important in biological and industrial applications. The measuring principle is based on detecting conductance and capacitance change with respect to the dielectric mass movement in the fringe electrical field. A three-dimensional finite-element formulation is employed in the dielectric material region and a small neighbouring region of the probe structure on which it is mounted. The electrical input admittance as well as the reflection coefficient are found from the finite-element analysis. From this, the conductance and capacitance related to the conical probe and fringing field are calculated and consequently the dielectric constant and loss factor are determined. In contrast to many other modelling techniques used for coaxial probe which are approximate and hence limited, the finite-element model is more exact and is applicable to complicated geometries. To demonstrate the accuracy of the numerical model, a parallel experimental study was carried out in the laboratory for the same geometric dimensions. The two results are compared and show excellent agreement, and also demonstrating that finite-element modelling is a good approach for optimized conical coaxial probe design. [ABSTRACT FROM AUTHOR]

The electromagnetic force between two misaligned coils (coils with parallel axes) with uniform current density distribution and rectangular cross section based on the derived semi-analytical expressions was presented. Using the semi-analytical expressions for magnetic force between filamentary misalignment circular coils we calculate the propulsive and the transverse magnetic force. In order to verify the validity of the expressions, we use the filament method with Grover's formula to calculate the magnetic force for two coils with parallel axes. The results obtained by two methods are in a very good agreement. In this paper, the derivation of the semi- analytical expressions and the calculation results of the magnetic force are introduced. [ABSTRACT FROM AUTHOR]

Systems that employ stimulating and implantable monitoring devices utilize inductive links, such as external and implanted coils. The calculation of the mutual inductance and the magnetic force between these coils is important for optimizing power transfer. This paper deals with an efficient and new approach for determining the mutual inductance and the magnetic force between two coaxial coils in air. The setup is comprised of a thick circular coil of the rectangular cross section and a thin wall solenoid. We use an integro-differential approach to calculate these electrical parameters. The mutual inductance and the magnetic force are obtained using the complete elliptic integrals of the first and second kind, Heuman's Lambda function and one term that has to be solved numerically. All possible regular and singular cases were solved. The results of the presented work have been verified with the filament method and previously published data. [ABSTRACT FROM AUTHOR]