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Fe-Cu-Nb-Si-B ribbons with creep-induced anisotropy fabricated by continuous stress-annealing were formed into toroidal cores. The temperature dependence of their magnetic loss and relative permeability at [B.sub.m] = 0.1 T was evaluated in the frequency range of 0.5-1 MHz and temperature range from room temperature to 523 K. We found that the cores can be used up to 523 K without magnetic property deterioration. This suggests that the proposed cores have superior high temperature properties compared with conventional gapped-ferrite cores allowing use at high temperature. Index Terms--Continuous stress-annealing, creep-induced anisotropy, high temperature properties, low permeability, magnetic core, nanocrystalline.

New metallic magnetic ribbons with permeability of several hundreds and magnetic loss comparable to that of Mn-Zn ferrites were developed by crystallizing amorphous Fe-Cu-Nb-Si-B ribbons. Although the magnetic properties of as-annealed ribbons showed remarkable unstability, they were stabilized by exposing the ribbon to large flux density before usage. The permeability of the stabilized ribbons could be adjusted to the desired value by controlling the flux density exposed for stabilization. The stabilized permeability was constant up to 400kHz independent of the excited flux density, as long as the excited flux density did not exceed the flux density used for stabilization.

Nd-Fe-B thin film magnets with the coercivity of approximately 7 kOe can be obtained using laser ablation technique. A suppression of oxidation and an optimization of post-annealing condition enable us to form [Nd.sub.2][Fe.sub.14]B phase and to achieve the thin films with high coercivity. Index Terms--Coercivity, laser ablation technique, Nd-Fe-B thin film magnets, post-annealing.

A laser ablation technique contained with a shadow mask in Ar atmosphere enables us to obtain crystalline ferrite thin films on glass substrates at room temperature. Investigations on the Ar pressure, [P.sub.Ar], and the distance between the shadow mask from the target, [L.sub.1], were carried out. The optimum conditions for forming the spinel structure of Mn-Zn ferrite were [P.sub.Ar] = 20 mTorr and [L.sub.1] = 20 mm, respectively. Index Terms--Coercive force, laser ablation technique, MnZn ferrite thin films, spinel structure.

(110) grain growth and magnetic properties in thin grain-oriented silicon sheets with ultimately low loss were investigated. A final-annealing at 1150 [degrees] C for 20 min enables us to obtain the thin sheets covered with only (110) grains and consequently the magnetic induction at 800 A/m, [B.sub.8], reached 1.9T. Index terms--final-annealing condition, magnetic induction at 800 A/m, (110) grain growth, thin-grain-oriented silicon sheets

Magnetic properties of thin 3% (100) textured silicon steel sheets with low loss were investigated. Annealing at 1200 [degrees] C in sulfur atmosphere enabled us to obtain the thin sheets containing only (100) grains and consequently the coercive force reached 10 A/m. We, further, advanced the production method of thin (100) textured silicon sheets by using sulfur in solution instead of a sulfur atmosphere, Index terms--Coercive force, (100) textured grains, sulfur, thin silicon steel sheets.

SmFeN film magnets were prepared by the laser ablation technique, and effects of film thickness and droplets on their magnetic properties were studied. An increase in the film thickcness increased coercivity. The thermomagnetic analysis and the X-ray photoelectron spectroscopy indicated that the observed increased in the coercivity can be attributed to the suppression of oxidation of Sm. Droplets on film surfaces included a large amount of Fe than flat parts without droplets and a decrease in the number of droplets results in an increase in coercivity. The coercivity of 6.5kOe was obtained for the 5 [micro]m thick film with a small number of droplets. Index Terms--Laser ablation technique, Sm-Fe-N thin film magnets, thickness, droplets.

Mn-Zn ferrite thin films with coercive force of approximately 4 kA/m were obtained by a low-temperature process using laser-ablation technique. Thin films were prepared at substrate temperature of room temperature in Ar atmosphere with a shadow mask using glass substrates. It was found that the spinel structure is formed in the films and that the surface roughness caused by large particles is improved. Index Terms--coercive force, laser ablation technique, MnZn ferrite thin films, spinel structure

\Smx\Co5/ \alpha\-{\Fe} multilayered structures were synthesized by the pulsed laser deposition (PLD) method from rotating composite targets composed of \Smx\Co5 (x = 1-5) and \alpha\-\Fe segments. The deposited films were approximately 10~\mu\m in thickness. Transmission electron microscopy observations revealed that as-deposited films were composed of Sm-Co and \alpha\-\Fe layers, 780 layers in total, with the well-controlled thickness of approximately 10 nm, and they are crystallized into structures composed of Sm-Co and \alpha\-\Fe nanograins. The (BH)\max versus \Sm/(\Sm+\Co) curve at room temperature showed clear peaks and the (BH)\max value of 100~\kJ/m^3 was obtained. Although the obtained (BH)\max value of \Sm\-\Co/\alpha\-\Fe nanocomposite thick film-magnets was comparable to that of \Nd\-\Fe\-\B/\alpha\-\Fe at room temperature, it exceeded those of \Nd\-\Fe\-\B/\alpha\-\Fe nanolayered magnets and rapidly quenched (Nd, Dy)-Fe-B flakes at 150 ^\circ\C. The large (BH)\max value of the \Sm\-\Co/\alpha\-\Fe nanocomposite thick film-magnet at 150 ^\circ\C can be attributed to its small temperature coefficient of coercivity, -0.34\%/ ^\circ\C. [ABSTRACT FROM PUBLISHER]

Nd-Fe-B/\alpha-Fe multi-layered thick film-magnets were synthesized by pulse laser deposition (PLD) method from a Nd2.4Fe14B/\alpha-Fe composite target. In order to improve magnetic properties and their reproducibility, effects of the stacking period of Nd-Fe-B/\alpha-Fe layers, tp, the target-substrate distance, DTS, and the laser beam energy on a target, EL, on them were studied. The reproducibility of magnetic properties was improved significantly by decreasing EL. In particular, the standard deviation of the Nd content was suppressed within 3%, when EL was reduced from a value higher than 200 mJ/mm^2 to 25 mJ/mm^2. An increase in DTS and selection of a suitable tp value improved the maximum energy product (BH)\max. The largest (BH)max value obtained in this investigation was 112 kJ/m^3, which is higher than the values reported previously for isotropic film-magnets thicker than 10 \mum. Origins of superior magnetic properties were discussed from the viewpoints of suitable interlayer exchange interaction between Nd-Fe-B and \alpha-Fe layers and morphology of prepared film-magnets. [ABSTRACT FROM PUBLISHER]