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Isotropic Nd-Fe--B thick film magnets were prepared by a high-speed pulsed laser deposition method followed by a post annealing. The deposition rate of 90 [micro]m/h could be successfully achieved, and a pulse annealing was adopted as the post annealing process in order to enhance coercivity. Use of a substrate heating system under the high deposition rate enabled us to obtain anisotropic thick films with [(BH).sub.max] of approximately 120 kJ/[m.sup.3], which show the potential for an improvement in the properties of the micromachines. Novel micromachines comprising the isotropic films were introduced. Index Terms--Laser ablation, micromachines, micromotors, thick film devices.

The steplike impedance change for thin-film giant magnetoimpedance (GMI) element is analyzed. The analysis has shown that the magnetic energy of the two phases have intersected each other in a certain external magnetic field, indicating that the basis of steplike GMI of thin-film element is disclosed as a structural change of magnetic domain based on magnetic energy.

Domain observation has been done to investigate the effect of strain due to a punching process on the magnetization process of a nine-slot core for 12-pole small brushless dc motor by using the Kerr microscopy technique. Stripe domain structures oriented to a transverse direction are observed at the edge of a tooth of the core without stress relief annealing. Due to the domain configuration, permeability near the punched edge of the motor core is reduced. A stress relief annealing at 700 [degrees]C for 2 h can relive the punching stress. Index Terms--Magnetic domain observation, nonoriented Si-Fe electrical sheet, punching process, stress relief annealing.

The pinning characteristics of a domain wall with a step-like thickness change along the wall is investigated in 0.15- to 0.5-[micro]m-thick films with an in-plane anisotropy using micromagnetic simulation based on the Landau-Lifshitz-Gilbert equation. The asymmetric Bloch wall having the structure in which the magnetostatic coupling develops between spins near the step when the wall is pinned shows the bi-directional pinning effect for magnetic fields applied along the magnetic domain. The wall energy of the pinned wall decreases with increasing step depth due to the largely decrease of the exchange energy component. The depinning field for the negative applied fields which drive the wall in the direction of the nongrooved region (thick film region) is considerably larger than that for the positive ones which drive the wail in the direction of the grooved region (thin film region). The depinning fields for both the positive and negative applied fields increase with decreasing film thickness. Index Terms--Domain wall pinning, groove, micromagnetic simulation, thickness variation.

Domain configuration of the nonoriented Si-Fe electrical sheets with different grain size was observed decreasing their sheet thickness by using the Kerr effect. It was found that the nonoriented sheet needs multiple grains in the sheet thickness direction to eliminate the normal magnetization component in the flux closing structure causing excessive eddy current loss. Index Terms--Anomaly factor, domain structure, grain size, nonoriented Si-Fe electrical sheets.

A new type of micro-pump using an angular movement of an elastic plate is proposed. The moving part of the pump consists of a small permanent magnet attached to an elastic plate. Iran alternating magnetic field is applied, the magnet vibrates angularly due to magnetic torque and then the polyimide film causes a unidirectional movement of fluid. A cm-size pump based on this mechanism has been constructed and tested. The maximum flow rate of 750 ml/min and the maximum pressure of approximately 4.2 kPa were achieved when ethyl alcohol was used as a working fluid. Index Terms - angular movement, micro-pump, permanent magnet, magnetic torque.

In this work we have studied the behavior of the bamboo domains under stress ([Sigma]), tension (+ [Sigma]) as well as compression (-[Sigma]), with the aim of making the domain model of the negatively magnetostrictive (-[[Lambda].sub.s]) CoSiB wire clear. It is observed that the growth of the surface bamboo domains due to [Sigma] has directivity depending on the orientation of the underlying core domain. In one orientation the black bamboo domain grows, while in the opposite orientation the white domain grows. From the stress behavior of the bamboo domains we have concluded that the domain model of -[[Lambda].sub.s], wire consists of two spiral domains of opposite rotation and proposed a new model. Index Terms - bamboo domains, domain model, spiral domains of opposite rotation, stress

A new electromagnetic rotary mechanism based on a friction drive has been proposed. The electromagnetic vibration on a permanent magnet was converted to rotary movement via a frictional force, and a trial motor, consisting of a magnet rotor, inclined legs and an excitation coil, was developed and successfully operated. A no-load revolution speed of up to 400 rpm and reversible rotation were obtained.

Magnetization process of amorphous ribbons in the hard axis of magnetization was investigated by observation of magnetic domains having the easy axis of induced anisotropy in the transverse direction. It was found that a field applied in the longitudinal direction caused wall motion as well as magnetization rotation through re-arrangement of energy balance between magnetostatic and wall energies. Re-annealing of ribbons in a remanent state without a magnetic field caused domain wall pinning that restrained wall motion and improved the magnetic properties at high frequency markedly.

The annealing behavior of a lanthanum oxide thin film deposited on a silicon (001) substrate by electron-beam evaporation has been studied by aberration-corrected transmission electron microscopy (TEM), scanning TEM (STEM), and electron energy loss spectroscopy (EELS). We have developed a procedure for the precise measurement of thickness and interfacial roughness by taking advantage of features of aberration correction combined with the statistics of fluctuating crystalline edge positions. The results of the measurements and quantitative elemental analyses by STEM-EELS have revealed atomic diffusion and reactions during deposition and postdeposition annealing (PDA) at 300 and 500 °C. The channel mobility could be limited by Coulomb scattering before PDA, and by remote roughness scattering and remote phonon scattering after PDA at 500 °C. When we consider the large leakage current caused by oxygen defects in the as-deposited sample and the large equivalent oxide thickness of the thick Si-rich layer in the 500 °C-PDA sample, the gate properties of the 300 °C-PDA sample should be better than those of other samples, as shown by electrical measurements. [ABSTRACT FROM AUTHOR]

The dependence of the magnetic properties of amorphous wire on the diameter have been investigated. The anisotropy constant, hence the internal stress, of the wire increases with the wire diameter. The size of the pinned reverse domain at the wire end increases with the wire diameter. Domain observation shows that irrespective of the change in the wire diameter, the domain structure basically consists of chevron domain layer sandwiched between the surface maze domain and the inner core domain.

Co-Fe-Si-B films have been prepared using a roll coater and DC magnetron sputtering system onto a polyethylene terephthalate substrate. This thin film exhibited an excellent uniaxial anisotropy introduced by an asymmetric thermal shrinkage of the substrate. Reversal with a single large Barkhausen pulse has been observed in a thin film structure 1mm by 50mm by 0.65 [[micro]meter]. Closure domains have been clearly identified at the film ends. The threshold for the reversal is the coercive force. The reason for reversal with a single Barkhausen jump is that the long narrow film geometry has essentially zero demagnetizing field over most of the film. Once the walls start to move through the center portion of the film, there is nothing to stop them so the reversal proceeds with a single large Barkhausen pulse.

Domain observations were made on Fe and Co based amorphous magnetic wires that exhibit a large Barkhausen discontinuity during flux reversal. Domain patterns observed on the wire surface were compared with those found on a polished section through the center of the wire. It was confirmed that the Fe based wire consists of a shell and core region as previously proposed, however, there is a third region between them. This fairly thick transition region made up of domains at an angle of about 45 degrees to the wire axis clearly lacking the closure domains of the previous model. The Co based wire does not have a clear core and shell domain structure. The center of the wire had a classic domain structure expected of uniaxial anisotropy with the easy axis normal to the wire axis. When a model for the residual stress quenched-in during cooling of large Fe bars is applied to the wire, the expected anisotropy is consistent with the domain patterns in the Fe based wire, however, shape anisotropy still plays a dominant role in defining the wire core in the Co based wire.

The field dependence of Young's modulus, E(H), of as-cast Fe-based amorphous wire has been investigated using a new high resolution vibrating reed system. The E(H) data have been combined with dc M(H) loops and Kerr effect surface domain images to provide new information about the effect of the large Barkhausen jump which characterizes the magnetization reversal in this material. At low-fields the modulus decreases via an abrupt small step which correlates with the field at which the large Barkhausen jump occurs in the M(H) behaviour. It is suggested that the reversal of the magnetization in the core domain leads to a slight rearrangement of domains in the sheath region of the wires. This is supported by the surface domain images and indicates a small asymmetry in the remanence states.

The mechanism of re-entrant flux reversal in Fe-Si-B amorphous wires was investigated by domain observation and reverse domain detection focusing on the magnetic properties near the wire ends. It was found that the wire consists of shell and core domains and that the core region has the residual reversing domain due to demagnetizing field near wire ends in a remanent state. The residual domain was stabilized by forming a flux closure structure through the shell domain, which increases the threshold field for domain growth to a value much larger than the wall coercivity and results in predominantly re-entrant flux reversal.

The article explains the domain structure, as well as the magnetization process employed in the hydrogenation disproportionation desorption recombination processed NduFeuB powder. The domain wall pinning effect is shown to lead to extremely high coercivity of these compounds.

A Kerr microscope is used for examining the domain structure and magnetization process of amorphous granular (CoFeB)-Si[O.sub.2] thin films. It is shown that wall motion causing excess eddy current losses at high frequencies is hard to occur by the granular structure.