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The influence of underneath magnetization of Nd-Fe-B sintered magnets on surface domain configurations was investigated using a Kerr microscope by cutting the magnets at an angle to the c-axis. When the angle formed by the surface and the c-axis is larger than 30 degrees, the observed domain configurations change to maze patterns because of an increase in the demagnetizing field at the surface. In contrast, when the cutting angle is 10 degrees, residual magnetization increases with the applied field. It was found that at a cutting angle of 10 degrees, the underneath domain configurations can be indirectly observed through the surface by propagation of magnetic flux from the underneath grains. [ABSTRACT FROM AUTHOR]

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 µm/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) of approximately 120 kJ/m³, which show the potential for an improvement in the properties of the micromachines. Novel micromachines comprising the isotropic films were introduced. [ABSTRACT FROM AUTHOR]

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 °C for 2 h can relive the punching stress. [ABSTRACT FROM AUTHOR]

The pinning characteristics of a domain wall with a step-like thickness change along the wall is investigated hi 0.15- to 0.5-μm-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 wall 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. [ABSTRACT FROM AUTHOR]

Describes the structure and basic characteristics of a micropump composed of a small permanent magnet and an elastic plate. Device structure; Results and discussion; Conclusions.

Investigates the magnetization of amorphous ribbons in the hard axis of magnetization having an induced anisotropy in the transverse direction. Experimental procedures; Results and discussion of the magnetization process of amorphous ribbons; Conclusions.

Presents a study which examined the behavior of the bamboo domains under stress, tension as well as compression with the aim of making the negatively magnetostrictive CoSiB wire clear. Experimental details; Results of the experiments; Conclusions.

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. [ABSTRACT FROM PUBLISHER]

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 thin film structure 1 mm by 50 mm by 0.65 /spl mu/m. 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. [ABSTRACT FROM PUBLISHER]