日本応用磁気学会誌

多層膜・人工格子

斜め蒸着Gd/Fe, Gd/Co人工格子のスピンフロップ現象

切明久, 土居邦彦, 縄手雅彦, 本多茂男

1992 年 16 巻 2 号 p. 281-284
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.281

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Gd/Fe and Gd/Co multilayers, prepared by an electron beam evaporation with oblique indidences, exhibit a uniaxial magnetic anisotropy in the film plane owing to the anisotropic atomic coupling at the interfaces. When bilayer thicknesses are between 16 Å and 22 Å for Gd/Fe and 12 Å for Gd/Co, the M-H curve for an easy direction at room temperature indicates a rectangular loop at low field and an abrupt increase in magnetization, i. e., a spin flopping occurs at about 0.5 kOe in Gd/Fe multilayers and about 1.0 kOe in Gd/Co multilayers.

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Fe/CoZr積層膜の軟磁気特性の熱安定性

神保睦子, 祖父江栄二, 綱島滋, 内山晋, 加藤哲男

1992 年 16 巻 2 号 p. 285-290
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.285

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Thermal stability of structural and soft magnetic properties were investigated for Fe/Co₉₂Zr₈ multilayers made by sputtering technique. Thermal stability of the coercive force is improved by using very thin bilayers. The good thermal stability is attributed to the suppression of the grain growth in the film plane. When the Fe layers are made thinner than 10 nm, a low coercivity less than 2 Oe can be obtained even after annealing at 600°C and an effective permeability of about 2000 after annealing at 500°C.

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CoNbZr/Ceramics複合異方性多層膜の磁気特性

菅原英州, 松本文夫, 藤森啓安, 増本健

1992 年 16 巻 2 号 p. 291-294
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.291

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The CoNbZr/ceramics multi-layers having sequentially changed anisotropy directions for CoNbZr layers in close contact with one another beyond ceramics layers were investigated. We call such a thin film “Composite Anisotropy Multi-Layers”, hereafter. The effect of this new multilaying method on B-H hysteresis loop and magnetic permeability was studied. When the number of CoNbZr layers is twelve and the value of the shift angle between the easy magnetization directions for the nearest neighbor CoNbZr layers is 45°, the smooth hysteresis loop with a low coercivity was obtained. Furthermore, this film showed a large permeability (μ') and an excellent frequency response. In addition, the μ' values remained unchanged by the bias fields of 2∼3 Oe. This finding is noteworthy for applications of magnetic devices, compared with the conventional uni-axial magnetic multi-layers in which permeabilities are changed by the applied bias field.

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Co/Pt多層膜の磁気特性に及ぼす基板バイアス効果

吾郷純也, 縄手雅彦, 本多茂男

1992 年 16 巻 2 号 p. 295-298
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.295

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Co/Pt multilayers were prepared by RF sputtering method. The substrate bias voltage V_B was applied during sputtering Co (or Pt) at the glass substrate, from 0 V to -70 V. In Co biased films, the perpendicular anisotropy K_u increases with V_B and shows maximum at -50 V, because the flatness and sharpness of the interface and the fcc (111) orientation become best at -50 V. The increase in K_u arises from the improvement of both the surface and volume anisotropy. On the other hand, in Pt biased films the mixing of Co and Pt occurs at the layer boundaries, resulting the decrease in K_u, for V_B ≥ -50 V.

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異なる背圧で成膜したCo/Fe多層膜の磁気特性に及ぼす熱処理の効果

海老沢孝, 徳重裕之, 宮川亞夫

1992 年 16 巻 2 号 p. 299-302
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.299

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The effects of post annealing on the magnetic properties of Co/Fe multilayer films sputtered with different background pressures (P'_B s) were examined. The films were deposited by DC magnetron sputtering with P_B of 1.0×10^-6 or 9.0×10^-8 Torr and were annealed in a vacuum at temperatures between 100°C and 600°C for 1 hour. Saturation magnetization of the films increased by the annealing at and above 300°C, indicating alloying of Co and Fe. Coercivity (H_c) of the films deposited with high P_B was 1 Oe before annealing; however, it increased by the annealing at and above 300°C. H_c of the films deposited with low P_B was 50 Oe before annealing, and it showed a rapid decrease when annealed at and above 200°C. reaching a minimum of 8 Oe at 500°C. The differences in magnetic properties with the P_B are mainly due to the difference in the oxygen content of the films.

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82Ni-Fe/Al-Al₂O₃/Co接合における磁気抵抗効果 −トンネルコンダクタンスの両磁性層の磁化の相対角度依存性−

矢追俊彦, 石尾俊二, 宮崎照宣

1992 年 16 巻 2 号 p. 303-308
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.303

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Magnetoresistance was studied for the ferromagnetic tunneling junction in 82Ni-Fe/Al-Al₂O₃/Co prepared by an electron beam evaporation in a vacuum of 1×10^-6 Torr. The tunneling is confirmed by measuring I-V character and its temperature dependence, which are in good agreement with Stratton's tunneling theory. The hysteresis curve of magnetoresistance corresponds well with that of magnetization. The magnetoresistance ratio ΔR/R is 2.7% and 3.5% at R.T. and 77 K, respectively. Dependence of the tunneling conductance (G) on the angle (θ) between the magnetizations of two ferromagnetic layers was also measured. The G-values can be expressed as G = G₀(1+ε cos θ) (G₀, ε: constant). which agrees well with the theory proposed by Slonczewski.

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Fe/Cr人工格子薄膜の磁気抵抗効果

久保田均, 石尾俊二, 宮崎照宣

1992 年 16 巻 2 号 p. 309-312
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.309

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Fe/Cr multilayers [Fe(20Å)/Crx]₂₀ (x = 5∼40Å) were prepared onto glass substrate by vacuum deposition metohd. Magnetization, ferromagnetic resonance and giant magnetoresistance were investigated. Both oscillation of magnetoresistance and interlayer exchange coupling as a function of Cr thickness were observed. Magnetoresistance was proportional to the saturation magnetic field H_s.

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(Co_xFe_1-x/Cu)_n人工格子膜の巨大磁気抵抗効果

斉藤好昭, 橋本進, 奥野志保, 柚須圭一郎, 猪俣浩一郎

1992 年 16 巻 2 号 p. 313-318
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.313

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We report that giant magnetoresistance (MR) at room temperature up to 50% for low field of 0.9 kOe can be attained in (Co_xFe_1-x/Cu)_n multilayers. A set of (Co_xFe_1-x/Cu)_n multilayers was prepared by the ion beam sputter deposition method on MgO(110) single crystal substrates. All samples were confirmed to have hexagona1 structure of Co_xFe_1-x by X-ray diffraction measurements. The hexagonal c-axis is in the film plane, which induces in-plane uniaxial magnetic anisotropy of the order of 10⁶ erg/cc. This anisotropy brings low saturation field in MR curves. We also investigated argon acceleration voltage (V_B) dependence of the MR ratio, which is quite large and has a maximum around V_B=600 V for [Co(10 Å) /Cu (10Å)]₁₆ and [Co₉Fe(10 Å)/Cu(10 Å)]₁₆ multilayers. In the preparation condition of obtaining the maximum MR ratio, almost perfect antiferromagnetic coupling of the Co_xFe_1-x layers via thin Cu layes is realized. We found that the MR ratio of Co_xFe_1-x/Cu multilayers is larger than that of h/ Cu multilayers in the higher Co-concentration range of the Co_xFe_1-x alloy.

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Co/Cu積層膜の磁気抵抗効果

三村哲哉, 大元誠一郎, 縄手雅彦, 本多茂男

1992 年 16 巻 2 号 p. 319-324
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.319

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Co/Cu multilayers were prepared by rf sputtering with and without the substrate bias voltage V_B= -30 V. X-ray diffraction indicated that the layer boundaries of -30 V biased films become sharper and the orientation of (111) planes becomes better than those of the films of 0 V bias voltage. In the films of 0 V bias, the MR ratio increases monotonically with Cu layer thickness, d_Cu, up to about 40 Å and then decreases. On the other hand, in the films of -30 V bias the MR ratio changes oscillatory with d_Cu, and the peaks appeared at d_Cu =23, 36 and 48 Å. The maximum MR ratio was obtained for the structure of [Co(15.1 Å) / Cu(24.3 Å)]₃₀/Cu(50 Å) and the value was 13.1% at room temperature and 17.0% at 110 K. In this film, the interlayer coupling strength J was very small, 0.008 erg/cm². Then the sharpness of the MR change, ΔR/R(H_s)·ΔH, was very large 2.2 kOe^-1. The different d_cu dependence for -30 V biased film from 0 V film was considered to be originated from the different quality of layer boundaries. The extraordinary Hall effect and the planer Hall effect are discussed.

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Co/Pt多層膜の磁気特性に及ぼす熱処理効果

森田昇, 縄手雅彦, 本多茂男

1992 年 16 巻 2 号 p. 325-328
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.325

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Co/Pt multilayers sputter-deposited with and without substrate bias V_B of -30 V were annealed in vacuum at 300 and 400°C. With annealing. the saturation magnetization M_s and the saturation Kerr rotaion angle θ_K increased. On the other hand, the perpendicular anisotropy energy K_u decreased manotonically. The decrease of K_u was larger for -30 V films than for 0 V films because of the larger decrease of surface anisotropy K_s for -30 V films. This larger decrease of K_s was discussed by taking account of relaxation in the lattice strain due to annealing.

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FePt/Pt人工格子の構造異常と光磁気特性

渡辺雅人, 高梨弘毅, 藤森啓安, 佐藤勝昭, 本宮秀俊, 本多茂男

1992 年 16 巻 2 号 p. 329-332
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.329

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Multilayer films (MLF's) composed of FePt ordered alloy and Pt were prepared by an ion beam sputtering method. X-ray diffraction in a low angle region indicated that the structural anomaly, leading to the absence of the multilayer periodicity, was seen in the case of the FePt layer thickness (d_FePt) round 50Å. The interplanar spacing along the perpendicular direction to the film plane increases for d_FePt around 50 Å. Furthermore, in the case of d_FePt around 50Å, the existence of an antiferromagnetic phase was also confirmed from the shift of the hysteresis loops at 4.5K in field cooling. Therefore, we consider that Pt-rich FePt alloy is formed in the FePt/Pt MLF's with d_FePt around 50Å. The spectral shapes of the θ_K and η_K spectra show a significant change for d_FePt > 50 Å and d_FePt < 50 Å. This fact suggests that the change in the electronic structure of the FePt/Pt MLF's occurs around d_FePt = 50Å. accompanied by the structural anomaly.

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MnSb/PtSb人工格子薄膜の作製と磁気光学特性

阿武俊彦, 新庄輝也

1992 年 16 巻 2 号 p. 333-336
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.333

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Multilayered films of MnSb/PtSb were prepared by alternately depositing Sb/Mn and Sb/Pt in ultrahigh vacuum, and structural, magnetic and magnetooptical properties were investigated. c-oriented epitaxial multilayers were obtained when the Sb/Pt layer is less than 2 monolayer thick (∼12Å) and the substrate temperature is between 110 and 125°C.

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センサー・磁気応用

完全反磁性体／磁界センサ体系による磁束源の検出

坂佐井馨, 荒克之

1992 年 16 巻 2 号 p. 337-342
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.337

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In this paper, the authors propose a new method for selective detection of magnetic-flux sources: i.e., current dipoles or magnetic dipoles, by a combined system of perfect diamagntic substance and a magnetic sensor. A good electric conductor such as copper behaves as a diamagnetic substance in highfrequency alternative magnetic fields in consequence of eddy currents induced on its surface. Experiments were carried out with high-frequency source dipoles and copper devices. It was proved that the method is very useful for selective and direct detection of magnetic flux sources.

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パラメトリックモータの設計法に関する考察

坂本禎智, 夏坂光男, 村上孝一

1992 年 16 巻 2 号 p. 343-346
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.343

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The parametric motor has many excellent features compared with ordinary single phase motors, and is expected to have many practical applications. In this paper, to make such motors more practically useful, the design method of the motor is discussed. That is, the relationships between the characteristics of the motor and the several dimensions of stators and rotors are investigated. As a result, we found a design method of dimensions of a stator and a rotor which gives the optimum distribution ratio of the flux in the stator used for parametric oscillation to the flux used for the motor operation.

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直交磁心を用いたリニアモータの動作に関する実験的検討

石川和己, 菊地新喜, 渡辺忠昭, 村上孝一

1992 年 16 巻 2 号 p. 347-350
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.347

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The paper described here is a description of experimental results on a orthogonal-core type linear motor with a new control system.
This orthogonal-core type linear motor has two power supply windings and the velocity or direction of moving parts can be easily controlled by the regulation of voltage phase difference between the primary power supply winding and the secondary power supply winding.
The excellent features obtained from the experiments are shown in this paper.

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渦電流制御に基づく磁束収束型電磁ポンプとその改良

別所一夫, 山田外史, 中野俊一, 山崎保

1992 年 16 巻 2 号 p. 351-354
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.351

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The electromagnetic pump proposed by the authors is concerned with the magnetic shielding effect by eddy currents in conductive plate. In this paper, we discussed the shape of the copper plate to control eddy currents by FEM analysis and the measured results. The proposed T-shape plate improves the shielding effect and the eddy-current losses compared with the preceding pump. In the closed circulating system for liquid alloy metal, we also confirmed the improvement of the thrust force.

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うず電流効果を利用した磁気歯車の始動特性改善

鶴本勝夫

1992 年 16 巻 2 号 p. 355-358
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.355

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The proposed noncontact magnetic gear using permanent magnet has many performance characteristics to remove gear noise and vibration. As the magnetic gear is an oilless machine element, it is useful to operate at clean and vaccum room.
But the magnetic gear tooth profile which is composed of a permanent magnet has a weak point in that it slips at high speed starting. For the practical use of the magnetic gear, this paper deals with the high speed starting method of the magnetic gear for connecting directly with the driving motor.
As a result, it was clarified that it is possible to start the trial magnetic gear at high speed, 1500 rpm, by utilizing the eddy current effect.

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出力リプル打ち消し回路によるDCPTの入力電力低減と周波数特性改善の検討

木脇久勝, 柳本富根

1992 年 16 巻 2 号 p. 359-364
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.359

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A novel circuit technology for input power reduction and frequency response improvement of DCPT was studied. First. proportionality between output ripple and output winding voltage ripple of DCPT was proved by circuit analysis. Secondly, a circuit aiming to cancel the output ripple by the winding voltage ripple was designed and its basic fuction was confirmed by experiments using a 60 Hz-driven DCPT (rated input power=80 W; natural frequency of reactor=12 kHz). As a residual pulsive voltage due to the natural oscillation of the reactor was observed in every half-cycle of 60 Hz, a time delay of about 60 microseconds was added to the cancellation circuit to reduce the pulse amplitude. Finally, the input power was reduced to 1/5 of that of the conventional DCPT and the frequency response nearly equal to that of ACPT (i.e., the reactor itself) was attained.

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ゼロフラックス制御型クランプ式電流センサの動作解析

鈴木康文, 山沢清人

1992 年 16 巻 2 号 p. 365-368
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.365

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A current measurement with wide frequency spectrum is required because of installation of semiconductor transfer facilites in industries. We proposed a current sensor with wide frequency range by AC zero-flux method. In this paper we analyze the mechanism of the operations. In particular we get a theoretical formula of the operation by taking a priority of CT operation at magnetic circuit. We developed a clamp-on current sensor with wide frequency range from 1 Hz to 500 kHz and good accuracy within ±0.5%. The analytical results agree well with the experimental data of the developed sensor.

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引張り · 曲げ応力に対する磁気異方性センサの動作比較

脇若弘之, 近藤和哉, 内山修一, 山田一

1992 年 16 巻 2 号 p. 369-372
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.369

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The magnetic anisotropy sensor (MAS) is noncontactly able to measure the mechanical stresses of ferromagnetic materials. The output voltage is caused by the inverse magnetostrictive effect. To measure tensile or bending stress, MAS output voltage − each stress characteristic was needed. This paper deals with the relationship of MAS output voltage for tensile and bending stresses. The output voltage on bending stress is calculated using the output voltage ratio and output voltage-tensile stress characteristics. Thus, MAS can measure both the tensile and bending stresses using output voltage- tensile stress characteristics.

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磁性半導体を用いた光センサの開発

関享士郎, 高橋知広, 千葉茂樹, 志田純一, 村上孝一

1992 年 16 巻 2 号 p. 373-376
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.373

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This paper describes the preparation and light response of the magnetic semiconductor photo-sensor (MSP). The MSP is composed of ferrite powder, binder, solvent and radiant flux absorbent. After the mixed magetic semiconductor fluid is printed by a spray gun, it is sintered at 800°C and its surface is covered with radiant flux absorbent. When the visible rays are radiated to the MSP, the radiant flux absorbent sucks in the light energy and the element temperature rises. Then, the MSP reluctance increases, so light-magnetic conversion is made. The light signal is read out by a Hall element. The MSP can be used for a photo relay, an illuminance meter and a photo coupler.

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L字形磁性体によるシャドウマスク周辺の磁界分布制御

奈須野裕, 鈴木寛範, 芳賀昭, 藤村健男, 山根啓介

1992 年 16 巻 2 号 p. 377-380
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.377

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An effective method of shielding an ambient magnetic field in the CRTs is presented. The key to this method is the use of the L-shaped strip iron. The L-shaped pieces are arranged with separation around the frame of the CRT. The new shielding method has the effect of reducing and reshaping the perpendicular field to the screen and reduces the color change. On the other hand, there are no effects from reducing and reshaping the parallel field to the screen.

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シャドウマスク孔の漏れ磁界の測定と電子ビーム軌道に対する影響

鈴木寛範, 芳賀昭, 奈須野裕, 藤村健男, 山根啓介

1992 年 16 巻 2 号 p. 381-384
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.381

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A shadow mask is made of a thin iron with plural electron beam through-holes. When the CRT is subjected to an ambient magnetic field, the shadow mask is magnetized and a stray magnetic field is created at the holes. Lorentz force causes a deflection of the electron beam when the beam travels through the hole. Stray magnetic field strength was measured by the SEM (scanning electron microscope). The stray magnetic field strength of a stripe type hole was 16.3 times as great as the ambient field. In order to clarify the influence of the stray field, we calculated the miss-landing. A little miss-landing is caused by the stray field.

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円柱鋼における磁気信号の長距離伝送特性の解析

坂田文男, 脇若弘之, 英貢, 山崎宣悦, 山田一

1992 年 16 巻 2 号 p. 385-388
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.385

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Magnetic signal transmitting method (MST) is a transmitting system in which magnetic flux is distributed on the boring rod (cylindrical steel rod). The boring rod is provided with a transmitting coil and receiving coil. At the pointed end of the boring rod, a sensor is provided to get information in the ground. The output power of the sensor becomes the input power of the transmitting coil. Magnetic flux is formed by the current in the transmitting coil. The sensor information is transmitted to the receiving coil by electromagnetic induction. MST aims at long distance transmission. In this paper, we experimented with the assessment of the input power on MST.

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超磁歪音響振動素子における磁気バイアスの効果

脇若弘之, 奈雲正通, 飯尾稔, 山田一, 五十嵐正夫, 小林圭一, 吉川隆

1992 年 16 巻 2 号 p. 389-392
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.389

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This paper deals with the effect of magnetic bias of Acoustic Vibration Element using Giant magnetostrictive material (AVEG) which is a low frequency transducer for an man acoustic tomography system. By measurement of magnetostriction characteristics, it is shown that the magnetic bias by magnet is a suitable value and the dynamic range must be less than I= ± 1[A].
The authors analyzed the magnetic circuit of AVEG and calculated the value of magnetic bias field.
And the structure of the magnetic circuit was evaluated with the next distinctive parameter. variation rate of magnetic dux density in the vibrator, effective rate of flux, and sensitivity of magnetostriction.

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極低温におけるマルテンサイト変態のその場帯磁率観察

喜多英治, 斉藤正克, 良本康久, 寺本徳郎, 田崎明

1992 年 16 巻 2 号 p. 393-396
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.393

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An ac susceptometer was constructed in order to carry out in situ measurement of susceptibility of stainless steel SUS316L specimens in tension tests under cryogenic temperatures. The susceptibility changes are responsible for the formation of ferromagnetic α'-phase due to martensitic transformation induced by a deformation in 4.2 K. The observed susceptibility became larger as the load was removed during the tension test. The stress induced magnetic anisotropy seems to lower the susceptibility under the tension. “True susceptibility” derived from successive loading and unloading experiment was speculated to reflect the amount of the martensitic part.

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パワーマグネティックス

アモルファス変圧器モデルの回転磁束分布

榎園正人, 戸高孝, 若山勝彦

1992 年 16 巻 2 号 p. 397-402
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.397

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Stacked three-phase three-limbed model transformer core has been assembled from POWERCORE strip sheet and the localized rotational flux distributions and distortion factors are measured using arrays of cross-type search coils. In the studies of two-dimensional magnetic properties for amorphous magnetic materials, we have reported that a remarkable anisotropy was observed under high magnetic flux density conditions. Therefore, it is necessary to make clear the influence of the anisotropy to the flux distributions at the T-joint part in the threephase transformer core. In this paper, the rotational flux distributions in the amorphous transformer core are investigated by using the three-phase threelimbed model core assembled POWERCORE strip.

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複素透磁率を用いた高周波用変流器の動作解析

藤原徹, 田原良一

1992 年 16 巻 2 号 p. 403-406
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.403

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This paper describes an analysis concerning the characteristics of current transformers (CT), considering the dynamic hysteresis loops of magnetic core. This analysis is performed using complex permeability to express magnetic hysteresis. This method is applied to CT with radio-frequency currents for switching power supplies, and the calculated results are in very good agreenent with the experimental ones. This analytical method is available for calculating the ratio of transformation and the phase angle of CT, and is useful in the design of CT.

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漏れ磁束を考慮した直交磁心の磁化特性の算定

田島克文, 一ノ倉理, 加賀昭夫, 穴澤義久

1992 年 16 巻 2 号 p. 407-410
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.407

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The orthogonal-core has various applications such as a parametric transformer and a DC-AC converter. The operating characteristics of the application devices can be calculated based on the measured flux-MMF relationship of the orthogonal-core. For the optimum design of the applications, we have to predict the flux-MMF relationship. However, in order to calculate the relationship, we need to solve the three-dimensional nonlinear problem. In this paper, we calculate the flux-MMF relationship based on the magnetic circuit model of the orthogonal-core. The computed results agree well with the experimental ones. It is obvious that the method on this study is valid for the calculation and useful for the optimum design of the applications.

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直交磁心形dc-ac変換器の三相化に関する検討

一ノ倉理, 斎藤寛礼, 田島克文, 秦泉寺敏正

1992 年 16 巻 2 号 p. 411-416
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.411

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In a previous paper, the authors proposed the orthogonal-core type dc-ac converter for photovoltaic power system. The dc-ac converter has desirable features including simple construction, high security and easiness of maintenance. The operating characteristics of the single-phase converter for residential photovoltaic power system have been reported. In this paper, we discuss the fundamental operations of the orthogonal-core type dc-ac converter for three-phase power system based on simulations and experiments. Desirable construction of the orthogonal-core type three-phase dc-ac converter has been clarified.

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整流器負荷を有するパラメトリック変圧器の動作解析

一ノ倉理, 田島克文, 秦泉寺敏正

1992 年 16 巻 2 号 p. 417-420
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.417

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This paper describes the push-pull parametric transformer constructed with a pair of orthogonalcores. Operating characteristics of the parametric transformer with rectifier load were analyzed based on the SPICE simulation. The analytical results show good agreement with the experimental ones. It has been clarified that the input surge current of the full-wave rectifier circuit with smoothing capacitor can be compensated by the parametric transformer. Use of the parametric transformer as the power stabilizer is expected because of its various functions including voltage regulation and overload protection.

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高周波磁気

ポリイミド上に作製したCo系アモルファス薄膜の軟磁性

加茂芳邦, 島田寛

1992 年 16 巻 2 号 p. 421-424
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.421

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CO-Nb-Ta-Zr amorphous films were fabricated on polyimide sheets. Thermal changes of the coercive forces and the uniaxial anisotropy field were investigated in order to obtain annealing conditions for improvement of the magnetic softness. The amorphous films on the polyimide sheets were found to exhibit good magnetic softness comparable to those on glass substrate. Based on those results the sheets were wound around a quartz bobbin and after annealing in a D.C. or rotating magnetic field, frequency dependence of the initial permeability was measured. Initial permeability as high as 2500 with little decay up to 30 MHz was obtained.

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高周波における軟磁性膜の透磁率測定と多層効果

千田正勝

1992 年 16 巻 2 号 p. 425-430
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.425

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This paper reports a new permeability measurement method at high frequencies (1 MHz∼1 GHz). An inductance-line with M/C/M structure was used to estimate permeability. The inductance-line made it possible to measure frequency characteristics of permeability up to GHz because of low straycapacitance and high resonance frequency. The magnetic film pattern was designed to ignore demagnetizing field, and permeability was estimated analyzing a magnetic circuit. With this method, the NiFe/SiO₂ and (Fe/SiO₂)/SiO₂ multilayer films were confirmed to show superior frequency characteristics by a factor of 20 to NiFe single layer film. Also, ferromagnetic resonance (FMR) was observed in these multilayer films at 650 and 750 MHz.

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多層薄膜磁心を用いた高周波薄膜インダクタ

白川究, 倉田啓明, 粕谷昌弘, 大沼繁弘, 鳥生次郎, 村上孝一

1992 年 16 巻 2 号 p. 431-436
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.431

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In this paper, thin film micro inductor was investigated from the stand point of increased quality factor (Q) and inductance (L). To obtain a high Q, it is important to use a magnetic core in which iron loss is small in high frequency. The thin micro film inductor was prepared using multi-layered CoNbZr/ AIN film. The best condition for high Q was investigated by changing the size of magnetic core and structure of multilayer and exciting coil. The Q and L are increased with decreasing thickness of one magnetic layer and increasing one interlayer. The demagnetization of open magnetic circuit of inductor is decreased by using multi-layered magnetic core. The stray capacitance between coil and magnetic core is dominant in these thin film inductors. It was found that multi-layered magnetic core is useful to increase the Q value and L of thin film inductors in high frequency. The experimental inductor in which iron and copper loss are decreased by multi-layered core and thick coil shows L= 120 nH, Q= 18 at 50 MHz in its size of 0.5 mm×2.5 mm×35μm

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薄膜磁心における分布磁束の等価回路表示に関する考察

山口正洋, 石原邦彦, 大関秀紀, 荒井賢一

1992 年 16 巻 2 号 p. 437-440
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.437

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Flux distribution in some inner-coil type thin film cores is discussed and equivalent magnetic circuits for the distributed flux are derived based on the theory of distributed constant circuit. The equivalent circuit has a simple structure and can give accurate inductance of the cores. Validity of the equivalent circuit is demonstrated for the sandwich type YIG inductor which exhibits forty times the inductance as a similar air core inductor. The equivalent circuit turns out to be mare simplified expression in the cases where the in-plane magnetic path in the magnetic film is very long and very short.

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薄膜平面コイル型インダクタの磁心配置に関する考察

松木英敏, 藤井信行, 白川究, 鳥生次郎, 村上孝一

1992 年 16 巻 2 号 p. 441-444
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.441

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Miniaturized thin film inductors with various shaped magnetic cores are described. The dimensions of these inductors are about 2 mm×2 mm. Since these are used at a frequency range above 100 MHz, we need to consider the effective utilization of magnetic core. We measured inductance with various shapes of magnetic cores in inductors, and investigated the flux density distribution. The inductors comprised 100∼240 pieces of magnetic cores is 1∼3. The conductor of these inductors is put on a single plane to avoid disconnection on the conductor. According to the measured results, the inductor which has the highest inductance per unit area is composed of 2-turns magnetic cores. There is no remarkable difference in inductance between closed loop core and open core.

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プレーナインダクタにおける銅損発生の機構

山口崇, 笹田一郎, 原田耕介

1992 年 16 巻 2 号 p. 445-448
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.445

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In this paper, conductive losses in a sandwichstructured planar inductor are discussed. The FDM (finite difference method) analysis of the current distributions in a rectangular conductor sandwiched with magnetic material revealed that the current crowds near the edge of the conductor. It is also shown that filling gaps with magnetic material is effective to reduce ac resistances, especially when the width of the conductor is much larger than the skin depth.

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生体磁気

睡眠脳磁図計測と脳内電源解析

上野照剛, 伊良皆啓治, 吉田秀樹

1992 年 16 巻 2 号 p. 449-452
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.449

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This study focuses on neuromagnetic approaches to the detection of brain electrical activities which are difficult to detect by EEG measurements. Sources of the delta waves during sleep in human subjects were investigated in the time and frequency domains. Both MEG and EEG activities were recorded simultaneously. The components of magnetic fields perpendicular to the surface of the head were measured using a DC SQUID with a second derivative gradiometer. A fast Fourier transform (FFT) was used to estimate the power spectrum. We observed that the frequency distributions were different for delta waves measured by MEG and EEG recordings. This frequency shift suggests that the sources which generate the magnetic fields are different from those which produce the EEG. The delta wave consists of many different sources with different frequencies. Some of these sources can be detected by MEG measurements, but are difficult to detect with EEG measurements.

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ソフトヒーティング素子の発熱機構に関する検討

高橋正彦, 家名田敏昭, 松木英敏, 佐藤知矢, 皆川栄, 菊地新喜, 村上孝一

1992 年 16 巻 2 号 p. 453-456
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.453

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Soft heating method for hyperthermia is an induction heating method utilizing iron loss of temperature-sensitive magnetic materials and maximal temperature is controlled by the Curie temperature. Heating seed is temperature-sensitive amorphous metal flakes which are composed of Fe-P-C-Cr. In this paper, some considerations on calorific power of temperature-sensitive amorphous metal flakes are described, in order to put the heating devices into tissue in clinical applications.

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完全埋込型人工心臓用非接触電力伝送の高効率化

松木英敏, 椎木元晴, 村上孝一, 山本孝幸, 仁田新一, 橋本弘之

1992 年 16 巻 2 号 p. 457-460
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.457

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This paper is concerned with electrical energy transmission by means of inductive coupling between two spiral coils with amorphous magnetic fibers. This method will be of use for transcutaneous energy transmission for an implantable artificial heart actuated electrically. As a result of an analysis of the operation of the transmitting coils, optimum operating condition for efficient energy transmission was found. The calculated result indicates that the transmitting coils are able to transmit electric power with about 95% of efficiency at the operating frequency of 100∼200 kHz. The average temperature rise of the coils of 2 or 3°C was observed while 20 W was transmitted. We also performed a test of energy transmission to a vibrating electromagnetic pump as an artificial heart.

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リニアモータ駆動型両心人工心臓の性能試験

山口昌樹, 矢野剛, 苅田充二, 山本行雄, 山田祥治, 山田一

1992 年 16 巻 2 号 p. 461-466
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.461

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In order to actualize an implantable use, a linear pulse motor-driven artificial heart, LAH-S91, with left and right blood pumps was studied continuously by the authors. Small size and high thrust actuators are required in the development of the LAH, and the evaluation method of a trial actuator is a problem one should not ignore. This paper deals with the results of performance test on LAH-S91 as follows: 1) Driving characteristics of the LAH-S91 are calculated using cardiovascular simulation. The thrust of LAH-S91 is insufficient for the life of a human being; it must be increased more than 10%. 2) The calculated value of the cardiovascular simulation approximately agrees with the experimental value of a mock circulatory system. 3) The maximum permissible loss of the LAH is defined by considering the cooling effect of the blood flow. The loss is 42 Watts, when the temperature rise is 1°C. The temperature rise is the subject for a future study.

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超伝導

溶融法で作成したYBaCuO系超伝導体の磁化緩和

天谷健一, 宮島英紀, 石川雄一, 小早志秀一, 吉澤秀二

1992 年 16 巻 2 号 p. 467-470
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.467

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The magnetic relaxation in high-T_c superconductors YBa₂Cu₃O₇ system prepared by modified melt-textured growth method was investigated. The relaxation rate, S, given by M^-1dM/d log (t), is independent of magnetic field and temperature below a given temperature. T₀, which is decreased with magnetic field. The pinning potential evaluated from the temperature-independent S is increased with temperature, but the potential is apparent. On the other hand, S in the range higher than T₀ is increased with temperature. This gives the potential dependent on log (J_c).

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高T_c酸化物超伝導体の磁場中冷却

牧野好美, 渡辺直寛, 岡本研正

1992 年 16 巻 2 号 p. 471-476
発行日: 1992/04/01
公開日: 2007/12/03

DOIhttps://doi.org/10.3379/jmsjmag.16.471

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We observed the asymmetries for the major loop and the DC bias field (H_b) dependence of the third harmonic component (V_3f) of the minor loop on the field cooled sample of a sintered Y-Ba-Cu-O superconductor disk. We investigated these asymmetries focusing on the minimum points of V_3f-H_b loop which are shifted by field cooling. We found that: (1) the minimum points of V_3f-H_b loop appear at the points that satisfied the zero field condition in the sample, (2) the inverse field for H_b caused by the vortex plays an important role in making the zero field condition in the sample, and (3) the asymmetries originate from the vortex induced by the field cooled process.

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