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Spinel ferrite Co-[gamma][Fe.sub.2][O.sub.3] films have advantages of high coercivity, high stability without protective layer, and low noise performance for magnetic recording layer. Also, exchange-coupled Co-Zr-Nb/Co-Sm underlayers showed superior characteristics. The Co-Sm hard magnetic layer pinned the domains of Co-Zr-Nb soft magnetic layer effectively and decreased the noise coming from the soft magnetic layer. Combining the Co-[gamma][Fe.sub.2][O.sub.3] recording layer and exchange-coupled Co-Zr-Nb/Co-Sm underlayers, the triple-layered perpendicular media showed abilities for ultrahigh-density perpendicular recording. Index Terms--Exchange-coupled underlayers, high-density recording, perpendicular magnetic recording media, spinel ferrite recording layer.

According to the system self-organization theory, an agent-oriented system is studied and built, which can self-program the object-oriented software for electromagnetic field computation. Index terms-Electromagnetic fields, software, automation, intelligent agent interaction.

The authors have developed a method of analysis which can examine the effects of the eddy current and hysteresis. In this paper, the method is applied to investigate the recording process of the MIG head and thin-film medium in the flexible disc drive. The effects of thickness and conductivity of thin sendust, and the recording current are clarified.

We have developed a computer program to optimize the coil distribution of the deflection yoke for CRTs. This program calculates changes of misconvergence and raster distortion by one additional winding. Then it modifies the coil distribution by minimization of the misconvergence. This program enables us to optimize deflection yokes in a short time.

Problems in analyzing 3-D stationary nonlinear magnetic field in non-oriented material taking into account hysteresis characteristics and eddy current, such as finite element formulation and convergence of nonlinear iteration, are discussed.

Factors affecting the results obtained by the optimal design method using the finite element and simulated annealing are investigated systematically, and the optimal parameters for simulated annealing method are obtained. The optimal shape of the die mold for orientation of magnetic powder is obtained using the finite element and simulated annealing. The experimental verification is also carried out.

A new type of 2nd order edge element has been proposed. Various kinds of triangular edge elements for 2-D electromagnetic field analysis are discussed in terms of definition of vectorial variables, shape functions and accuracy. It is illustrated that the new edge element is more favourable than other 2nd order edge elements from the standpoints of accuracy and selection of variables. The new element can be extended easily to higher order elements and to 3-D elements.

The effect of the scalar potential [Theta] in the A-[Theta] method on the convergence characteristic of the Incomplete Cholesky Conjugate Gradient (ICCG) method using the edge element is investigated. Several 3-D eddy current models are analyzed both by taking into account [Theta] and neglecting [Theta] to compare the convergence characteristics. It is illustrated that the CPU time using [Theta] is less than 1/2 of that neglecting [Theta], and there are some models in which the use of [Theta] enables us to obtain convergent solutions.

A method for linear analysis of ac steady state eddy currents in a moving conductor using a moving coordinate system is investigated. It is shown that the moving coordinate system is superior to a fixed coordinate system for the analysis of a high speed conductors from the standpoint of stability of the solution. The applicable extent of the moving coordinate system is also discussed.

Distribution of temperature and electric field at the joint of a dc power cable is analyzed taking into account the nonlinearity of electric resistance which is a function of temperature and electric field strength.

A practical 3-D finite element method using edge elements for analyzing stationary nonlinear magnetic fields with eddy currents in electric apparatus, in which the flux interlinking the voltage winding is given, has been proposed. The method is applied to the analysis of magnetic fields in the Epstein frame.

The effects of the continuity of the magnetizing current density on the convergence of the incomplete Cholesky conjugate gradient method and the accuracy of the calculated flux densities are investigated by imposing different continuity conditions for both nodal and edge elements. It is shown that the continuity condition should be imposed precisely in the case of edge elements.

Requirements for a model to verify software for 3-D static force calculation ar examined, and a 3-D model for static force calculation is proposed. Some factor affecting the analysis and experiments are investigated in order to obtain accurate and reproducible results.

The method for analyzing flux distributions in transformer cores made of grain-oriented silicon steel is improved in order to reduce error in calculatio due to anisotropy in magnetic materials. A model to verify the improved method is proposed, and the calculated results are compared with measured ones.

The cylindrical boundary element method is extended to analyze a three-dimensional configuration such as a deflection yoke with a slot core. The analyzed results are compared with the measurements and the peak field discrepancy is less than 1%. Furthermore the beam convergence characteristics on the screen surface are compared with the measured pattern and it is found that the numerical convergence error is less than 0.2 mm. As for the computation time, the matrix calculation and its solution time is reduced by a factor of 9 in comparison with conventional three-dimensional analysis. The field calculation time is also improved to 0.061 sec/point, which is 6 times faster than by conventional analysis.

In order to reduce the CPU time for the modified Newton-Raphson method which introduces a relaxation factor, the effect of the relaxation factor on the residual of the Galerkin method is examined in detail. It is shown that a relaxation factor, which always provides convergent solutions, can be easily searched for. Various methods for searching for the relaxation factor to be used are compared with each other.

This paper presents a simple algorithm yielding unique face subdivision patterns of locally refined tetrahedral elements by the Delaunay tessellation process. Due to numerous advantages of edge elements, the algorithm is combined with the magnetostatic edge element computer code. Next, a comparative analysis of four different error estimates used to locate elements for refinement, including a new one suitable for edge elements, is described. Finally, the performance of the presented algorithm and the effectiveness of the error estimates are demonstrated by means of three-dimensional test problems.

A new 3-D adaptive mesh refinement scheme using a nonconforming elements is investigated. It is shown that the accuracy of the analysis using the new 3-D adaptive mesh refinement can be improved compared with that using the conventional conforming mesh. The increase in CPU time for the new adaptive mesh refinement is not so large.

xFe/(100-x)(NiZnCu)[Fe.sub.2][O.sub.4] (x: wt%) composite films were prepared by the aerosol deposition (AD) method. The as-deposited x = 80 film exhibited the maximum relative permeability of [[mu]'.sub.r max] = 18 at around 450 MHz. The AD film also showed [[mu]'.sub.r] = 9 at 3 GHz, which were comparable to the values obtained with a heat-treated NiZnCu ferrite AD film. The result of transmission and reflection measurements revealed that these composite films have high potential for noise suppressors in the gigahertz range. In particular, the maximum of pure power loss ([DELTA] [P.sub.loss]/[P.sub.in]) of 0.68 have been obtained in the x = 4 film. Index Terms--Aerosol deposition method, composite film, ferrite, noise suppression, permeability.

The flux distribution and static force of a novel brushless dc linear motor were calculated by 3d finite element analysis. An analytical model to increase the force to volume ratio of the motor was validated by the numerical analysis as well. Experimental and numerical results present an excellent closeness.

A new method for measuring the magnetostriction of silicon steel sheet using a laser doppler velocimeter has been developed. This method has the following advantages: (a) non-contact measurement, (b) better resolution (less than 4 X [10.sup.-8]m under the condition that the error is within 1%) than conventional methods, (c) measurement of magnetostriction in any direction of anisotropic material and (d) little operator skill required.

The use of linear pulse motors (LPM) have increased in industry because of the desirability of direct drive for control. The authors have developed the Claw-Pole Linear Pulse Motor (CP-LPM) which is a linear version of a rotating PM type stepping motor. In this paper, we investigate inductor specifications inthe CP-LPM. Measurements of flux density confirmed the hypothesis that modifying inductor shape from rectangular to trapezoidal makes magnetic saturation difficult. Increasing pole pitch Tau also improved magnetic characteristics.

A new technique for measuring B-H curves of grain-oriented silicon steel along arbitrary directions has been developed. As the control of waveform is not necessary in the new technique, it is possible to measure B-H curves up to high flux densities which are required for calculating flux distribution using the finite element method.

In order to investigate the cause of quenching at the joint between a multifilamentary superconducting cable and a normal conducting cable, the 3-D current distribution is analyzed. It is found that the cause of quenching is the extreme concentration of current in the joint due to the pronounced skin effect at liquid helium temperature. The mechanism of the concentration of current which is affected by the twist pitch and skin depth is also clarified quantitatively by numerical analysis.

When the dc magnetization curve (B-H) of non-oriented material is measured in a ring specimen, there is an intrinsic error due to the assumption that the mean magnetic path length is equal to the mean geometric path length. In this paper, a new method for determining the B-H curve accurately is proposed. The validity of the method is verified by experiments.

A new type of transformer with reduced iron loss, which is excited by a semirotating magnetic field, has been investigated. Factors (method of excitation and slits in the core) affecting iron losses are examined. The iron loss of the new type of transformer can be reduced below the material loss as measured for normal ac excitation by introducing a slit which cuts the eddy current path, and by improving the method of excitation.

We described the pulsed-laser deposition (PLD) and characterization of cerium doped yttrium iron garnet (Ce:YIG, [Ce.sub.0.6][Y.sub.2.4][Fe.sub.5][O.sub.12]) thin films for magnetic field sensor applications. It was found that crystallized Ce:YIG films were obtained by the deposition at 900 [degrees] C substrate temperature and in 10 mtorr argon or oxygen ambient gas. The Faraday rotation angle was very large; 4.2 deg/[micro]m at 430 nm wavelengths. The charge state control of cerium was important for the crystallinity and high Faraday rotation. The lower temperature or higher ambient gas pressure controlled the cerium charge state [Ce.sup.4+], because the oxygen and cerium released from an ablated target accelerated to form cerium oxide, the thin film was noncrystalline and no Faraday rotation occurred. Index Terms--Cerium substituted yttrium iron garnet, Faraday rotation, pulsed laser deposition, x-ray photoelectron spectroscopy.

We have proposed an improved power-series expansion method for the analysis of magnetic deflection yokes in a cathode-ray tube (CRT). The magnetic field is expanded to either of two different power-series formulations, depending on the radial position from the central axis of the deflection yoke. The coefficients of the power series are calculated by symbolically differentiating the magnetic field expressed by the surface magnetic charge method formulation. The boundary position for selecting either of the two formulations and the required highest order of the power series are determined by minimizing the summation of squared differences between the magnetic fields given by the proposed method and those given by the surface magnetic charge method at an off-center position. We compared the speed of the proposed method with the conventional surface magnetic charge method and evaluated the picture quality on a screen. We found that the calculation time for the misconvergence was reduced to 1/63 that of the conventional method, with an accuracy of [+ or -] 0.4 mm. Index Terms--CRT, deflection yokes, surface magnetic charge method.