Magnetic tunnel junctions (MTJs) consisting of GdFe/Al oxide/Co/TbFe layers were fabricated. The GdFe and TbFe layers were perpendicularly magnetized, and the TbFe and Co layers were exchange-coupled with each other. Magnetoresistance (MR) curves were measured for MTJs with Co layers of various thicknesses while applying a field perpendicular to the film plane. The MR ratio showed a maximum of 12.1% when the Co layer thickness was 0.5 nm. Calculation using a noncontinuum model showed that the direction of the Co magnetization in the exchange-coupled film was perpendicular to the film plane when the thickness of the Co layer was less than 0.4 nm, which was consistent with measured magnetization curves as well as the results of simulation.

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A remote interrogatable highly sensitive stress sensor based on soft magnetic magnetostrictive amorphous FeCoBSi thin films has been developed. This sensor is very interesting for stress and torque measurements on rotating or hidden objects. It consists of a resonating circuit (LC-tag) with a magnetically sandwiched strip inductor and a thin film capacitor. The resonance frequency of this device is about 500 MHz with quality factors about 8. A figure of merit of 1600 was reached with such devices.

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Co_79.6 Fe_4.6 Si_9.2 B_2.7 Mo_3.9 amorphous fibres were produced by the modified melt-extraction process. Studied fibres exhibit GMI ratio of the order of 50% in as-cast state which is connected to their soft magnetic behaviour and small magnetostriction constant. Effect of ac current frequency and amplitude and current annealing (current intensity from 88 to 95 mA, annealing time up to 28 min)on GMI effect has been studied.

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The dependence of magnetoimpedance ratio, ΔZ/Z = {[Z(H)-Z(H_max)]/Z(H_max)}.100%, on the axial magnetic field of soft magnetic Co₆₇Fe_3.85Ni_1.45B_11.5Si_14.5Mo_1.7glass coated amorphous microwires has been investigated in the frequency range 1 - 30 MHz, for the driving current amplitudes 0.75 - 5 mA, and at the maximum axial DC-field of 8 kA/m. In the as-prepared sample, maximum GMI ratio, ΔZ/Z_max≈380%, has been observed at the highest used frequency (30 MHz). It has, however, been shown, that Joule heating enables to enlarge the ΔZ/Z_max ratio up to 500%. A strong dependence of ΔZ/Z_max on annealing time, frequency and amplitude of the driving current has also been observed. The results of the GMI measurements, presented as a function of the annealing time with the frequency and current amplitude as the parameters, showed an increase of the anisotropy field with an increase of the annealing time and temperature. The observed dependencies have been interpreted in terms of stress relaxation and changes of the magneto-elastic anisotropy induced by the Joule heating.

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Thin-film inductors for dc-to-dc converters for microprocessor power delivery are discussed. Thin-film inductors offer small size and fast transient response as required by the application. The choice of magnetic material and design of the inductor are discussed. Composite granular metal-nonmetal films applied in a Vgroove stucture show strong promise for this application. The possibility of using magnetic films with stripe domains is also discussed.

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Two types of conducted noise suppressors usable in a GHz range were fabricated using Ni-Zn ferrite films deposited from aqueous solutions. One is a direct-deposition type, in which Ni-Zn ferrite films are deposited directly on a microstrip line on an epoxy printed circuit board (PCB). The other is a sheet-type, in which the surfaces of Ni-Zn ferrite films deposited onto the polyimide sheet are in contact with the microstrip line. The direct-deposition type, using Ni-Zn ferrite film 3μm thick, exhibited a strong transmission loss of 40 to 70% at 1.5-10 GHz, which far exceeds that obtained for commercial composite sheet type of noise suppressors (50μm thick), in which fine ferromagnetic flakes are dispersed in a polymer matrix. The sheet type suppressor using Ni-Zn ferrite film exhibited better transmission loss and reflection loss than those of composite sheet type of noise suppressor, though the ferrite film 5 μm thick was much thinner than composite sheet 50 μm thick.

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The RF electromagnetic noise attenuation on coplanar transmission line was investigated using the newly The RF electromagnetic noise attenuation on coplanar transmission line was investigated using the newly developed spin sprayed Ni-Zn(-Co) soft ferrite films with high resistivity. The RF noise suppressor was composed of magnetic film/polyimide/Cu coplanar transmission line/seed layer on glass substrate. The coplanar transmission line with a characteristic impedance of 50 Ω had a 50 μm-wide and 3 μm-thick signal line. The power loss of the coplanar transmission line with Ni-Zn(-Co) ferrites using insulating layer between the transmission line and magnetic film was smaller than that of CoNbZr films at GHz range. It is due to the high resistivity (517×10²Ωcm-240×10³Ωcm) of the ferrite films in comparison with that of the metallic magnetic CoNbZr film (120 μΩcm). The power loss of the coplanar transmission line using the ferrite films without insulating layer was compared with that of CoNbZr with a 7.5-μm-thick insulating layer. The power loss of the ferrite films without insulating layer was as large as that of the CoNbZr film with insulating layer over 1 GHz.

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A new permeameter for both metallic and insulative thin-films is proposed for up to 9 GHz range. The film sample is driven by a traveling electromagnetic field and the output signal is sensed by a planar shielded-loop coil. The electric field induced voltage at the pickup coil can well be suppressed by the nature of the planar shielded-loop coil. Measurements on an amorphous CoNbZr thin film and a granular CoZrO thin film were demonstrated.

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