論文 - 能崎　幸雄

サブμｍ幅磁性多層膜細線の磁気抵抗特性

松尾 健一, 松山 公秀, 能崎 幸雄

日本応用磁気学会誌 （The Magnetics Society of Japan）  23 （ 4 ） 1249 - 1252 1999年

筆頭著者, 最終著者, 責任著者, 査読有り,  ISSN  0285-0192

　概要を見る

GMR-like behavior was observed in magnetic strips consisting of a symmetric layer structure with pattern widths down to 0.2 μm, and was significantly different from that observed in as-grown samples. The dependence of the MR saturation field on the pattern width agrees well with a theoretical prediction based on a coherent rotation model. The MR ratio was markedly increased by increasing the number of layers and the thickness of the magnetic layers; the highest value of 7.8% was obtained for a strip made of [Co(6 nm)/Cu(4 nm)]₂/Co(6 nm). A linear and hysteresis-free MR response was obtained with an alternating field modulation under a transverse bias field. A thickness dependence of the GMR property implies that the probable cause of the antiparallel spin orientation in the strip pattern is magnetostatic interaction between the surface magnetic charges at the pattern edges.

• Access to Document (DOI)

Magnetic and electric properties of SnOx/M (M=Fe, Ni, Co) multilayers

Kimihide Matsuyama, Katsunori Nishihata, Shinya Komatsu, Yukio Nozaki

Digests of the Intermag Conference （IEEE）  1999年

筆頭著者, 最終著者, 責任著者, 査読有り,  ISSN  0074-6843

　概要を見る

Discussed is a spin dependent current perpendicular to plane (CPP) transport observed in a novel semiconductive-oxide/ferromagnet multilayers of [SnOx(6 nm)/M(t nm)×10 (M=Fe, Ni, Co), deposited with a multi-target magnetron sputtering system. This transport property is dominated by the local region of the current path, where the magnetostatic coupling due to the interlayer roughness causes the antiparallel spin configuration in the remanence state.

Magnetization reversal process in micron size ferromagnetic Co line array

Y. Nozaki, T. Ono, K. Motohashi, H. Miyajima, and T. Kinoshita

Journal of Magnetism and Magnetic Materials （Elsevier）  177   1271 – 1272 - 1272 1998年01月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0304-8853

　概要を見る

The magnetization reversal process in a lithographic Co line array was investigated. The coercive force parallel to the Co line increases with the spacing between the Co lines. (C) 1998 Elsevier Science B.V. All rights reserved.

パルス磁場を用いたＢｉ系酸化物超伝導体における磁束の粘性力の測定

小林心, 能崎幸雄, 宮島英紀,本橋一成, 木下岳司

Journal of the Magnetics Society of Japan （日本応用磁気学会）  21 （ 4-2 ） 397 – 400 1997年04月

研究論文（学術雑誌）, 共著, 査読有り

Magnetic flux penetration process in two-dimentional superconductor covered with ferromagnetic particle array

Y. Nozaki, Y. Otani, K. Runge, H. Miyajima, B. Pannetier, J. P. Nozieres, and G. Fillion

Journal of Applied Physics （The American Institute of Physics）  79 （ 11 ） 8571 – 8577 1996年06月

研究論文（学術雑誌）, 共著, 査読有り

Magnetic flux penetration process in two-dimensional superconductor covered with ferromagnetic particle array

Y Nozaki, Y Otani, K Runge, H Miyajima, B Pannetier, JP Nozieres, G Fillion

JOURNAL OF APPLIED PHYSICS （AMER INST PHYSICS）  79 （ 11 ） 8571 - 8577 1996年06月

筆頭著者, 最終著者, 責任著者, 査読有り,  ISSN  0021-8979

　概要を見る

The magnetostatic effect of a ferromagnetic particle array on an underlying two-dimensional superconducting Nb thin film was investigated in terms of flux penetration processes by means of high sensitive magnetometry. For bare Nb film, a large drop in magnetization due to a flux rearrangement appeared in the low field region below 2.5 mT. However, once magnetic particles were fabricated on the surface of the Nb film, the drop was not observed. In this configuration, the ferromagnetic particles seem to behave as flux guides for the external magnetic field, whereby the flux distribution inside the superconductor is well regulated. Furthermore, a periodical oscillation was observed in the hysteresis loops. This behavior is associated with a flux quantization in the regions where the superconductivity is suppressed by the stray field of the ferromagnetic particles. The local flux density distribution around the ferromagnetic particles was evaluated by using the London equation, and the magnetization curve of the Nb film with periodically modulated superconducting order parameter was calculated. (C) 1996 American Institute of Physics.

試料共振型高感度磁力計

宮島英紀，本橋一成, 能崎幸雄, 大谷義近, 増田宏

Journal of the Magnetics Society of Japan （日本応用磁気学会）  20 （ 5 ） 919 – 921 1996年05月

研究論文（学術雑誌）, 共著, 査読有り

試料共振型磁力計による微小磁気モーメント測定

能崎幸雄, 宮島英紀，大谷義近，増田宏，本橋一成，眞砂卓史，K Runge

Journal of the Magnetics Society of Japan （日本応用磁気学会）  20 （ 2 ） 297 – 300 - 300 1996年04月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0285-0192

　概要を見る

A new type of highly sensitive magnetometer called a resonating sample magnetometer (RSM) is described. A magnetic sample is mounted on the end of a cantilever rod that incorporates a flat spring with a pick-up coil. The sample is magnetized in a de field, -5 kOe<<i>H</i>_a< +5 kOe,and is simultaneously subjected to a small ac field gradient.The ac field gradient exerts an alternating magnetic force on the sample, proportional to the sample's magnetic moment. The resulting oscillation of the rod is greatly amplified by using the mechanical resonance of the flat Elinvar spring, whose elastic modulus is almost constant in response to temperature variation. The deflection is measured by the pick-up coil. The RSM is considered as a possible system for measuring the temperature variation of magnetization. At room temperature, the sensitivity of the RSM is 6 × 10^-7 emu, and a complete hysteresis loop can be measured in about 15 min.

• Access to Document (DOI)

超伝導体と軟磁性体の複合体の磁化特性

津山祥紀，大谷義近，眞砂卓史, 能崎幸雄, 宮島英紀

Journal of the Magnetics Society of Japan （日本応用磁気学会）  20 （ 2 ） 449 – 452 - 452 1996年04月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0285-0192

　概要を見る

The magnetization process of a hybrid system composed of a soft magnet (Fe-Si) and a superconductor (Bi₂Sr₂Ca₂Cu₃O_<i>x</i>) is investigated from the viewpoint of the magnetostatic coupling interaction. The residual magnetization of the hybrid system is higher than that of the superconductor, while the susceptibility is lower than that of the Fe-Si alloy. The behavior is interpreted as due to the occurrence of magnetic image in the superconductor and also to the magnetic flux pinning at the corner of the superconductor.

• Access to Document (DOI)

Magnetostatic effect on magnetic flux penetration in superconducting Nb film covered with a micron-size magnetic particle array

Y. Nozaki, Y. Otani, K. Runge, H. Miyajima, B. Pannetier, and J. P. Nozieres

Journal of Applied Physics （The American Institute of Physics）  79 （ 8 ） 6599 – 6601 - 6601 1996年04月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0021-8979

　概要を見る

Magnetostatic effect of the micron-size ferromagnetic particle array on a two-dimensional superconductor was investigated. In the bare Nb film, a sharp drop in magnetization due to the flux rearrangement was observed, whereas this behavior was not observed for the Nb film with the ferromagnetic particles arranged on top. The difference in the magnetization curves may be attributed to the regulated flux penetration process by the ferromagnetic particle array. (C) 1996 American Institute of Physics.

High-resolution observation of magnetization processes in 2um x 2um x 0.04 um permalloy particles

K. Runge, Y. Nozaki, Y. Otani, H. Miyajima, B. Pannetier, T. Matsuda, and A. Tonomura

Journal of Applied Physics （The American Institute of Physics）  79 （ 8 ） 5075 – 5077 1996年04月

研究論文（学術雑誌）, 共著, 査読有り

High-resolution observation of magnetization processes in 2 mu mx2 mu mx0.04 mu m permalloy particles

K Runge, Y Nozaki, Y Otani, H Miyajima, B Pannetier, T Matsuda, A Tonomura

JOURNAL OF APPLIED PHYSICS （AMER INST PHYSICS）  79 （ 8 ） 5075 - 5077 1996年04月

筆頭著者, 最終著者, 責任著者, 査読有り,  ISSN  0021-8979

　概要を見る

The magnetization process in an array of 2 mu m x 2 mu m x 0.04 mu m permalloy particles fabricated on a 100 nm carbon membrane was investigated by means of high-resolution Lorentz microscopy and electron holography in magnetic fields parallel and perpendicular to the film surface. For perpendicular fields, the magnetization reversal was found to begin with the nucleation of a vortex which gradually transformed into a closure domain configuration. At the remanent state, the flux closure was achieved with the generation of a new type of doubled domain wall. (C) 1996 American Institute of Physics.

Hydrogenation characteristics and magnetic properties of fine Ni particles coated with Pd

Y. Otani, H. Miyajima, M. Yamaguchi, Y. Nozaki, T. Manago, A. J. Fagen, and J.M.D. Coey

Journal of Magnetism and Magnetic Materials （Elsevier）  140-144   403 – 404 - 404 1995年02月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0304-8853

　概要を見る

Hydrogenation characteristics and magnetic properties of Ni fine particles with thin Pd shell were investigated. The Pd shell appeared to turn weakly ferromagnetic below about 20 K, but this magnetic polarization was suppressed by hydrogenation.

Magnetic flux penetration process in superconducting Nb film covered with lithographic array of ferromagnetic particles

Y. Otani, Y. Nozaki, H. Miyajima, B. Pannetier, M. Ghidini, J.P. Nozieres, G. Fillion, and P. Pugnat

Physica C （Elsevier）  235-240   2945 – 2946 - 2946 1994年12月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0921-4534

　概要を見る

The effect of a micron size Sm33Co67 or Fe-Ni ferromagnetic particles array fabricated on a 2D superconducting niobium film was investigated by means of a magnetoresistivity measurement and rotating SQUID magnetometry. The magnetic particles seem to act as flux accumulators or flux guides through which flux lines penetrate inio the superconducting Nb film.

Magnetic properties of fine Ni particles coated with Pd

Y. Otani, H. Miyajima, M. Yamaguchi, Y. Nozaki, A. J. Fagen, and J.M.D. Coey

Journal of Magnetism and Magnetic Materials （Elsevier）  135 （ 3 ） 293 – 297 - 297 1994年08月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0304-8853

　概要を見る

Magnetic properties of Ni fine particles (0.7 mu m in diameter) coated with Pd (5-30 nm thick) were studied before and after hydrogenation. The system offers the possibility of studying hydrogenation under isovolumetric constraint, but this seems to produce little change in the saturation loading. The Pd shell appears to turn weakly ferromagnetic below about 20 K under high magnetic fields, but this magnetic polarization is suppressed by hydrogenation. The lowering of the magnetization of Ni by Pd coating may be related to a change in the surface anisotropy of Ni.