1999 Fiscal Year Annual Research Report

微小磁性体の作製とその性質

Research Project

Project/Area Number	09236103
Research Institution	KYOTO UNIVERSITY
Principal Investigator	新庄輝也京都大学, 化学研究所, 教授 (70027043)
Co-Investigator(Kenkyū-buntansha)	松井正顕名古屋大学, 工学部, 教授 (90013531) 高橋研東北大学, 大学院・工学研究科, 教授 (70108471) 大越正敏九州工業大学, 情報工学部, 助教授 (90112177) 片山利一東邦大学, 薬学部, 教授 (10307770) 宮島英紀慶應義塾大学, 理工学部, 教授 (70166180)
Keywords	微細加工磁性体 / 巨大磁気抵抗効果 / トンネル磁気抵抗効果
Research Abstract	新庄は微細加工法によって作製した磁性細線における磁壁の動的挙動を、電気抵抗を通じて研究する新しい手法を開発した。すなわち細線は磁性・非磁性・磁性の三層構造からなり、非結合型GMR効果によって電気抵抗の測定から磁化の向きを知ることができる。この方法を利用した結果、サブミクロン幅の細線では磁化反転は一個の磁壁の移動と見做せることは既に報告したが昨年までの測定では磁化反転磁場にはかなりのばらつきが見られた。今回測定端子部分を非磁性金属(Cu)で作製することにより、磁化反転磁場が再現性のある値となり、磁壁核生成を制御することに成功した。細線の一端にパッドを付した時、磁壁はパッドと細線の結合部分でトラップされ、磁場が一定値に達すると伝播を始めることが確認された。0.1ミクロン以下の超細線については新庄、宮島のグループの共同で研究されており、シャドウマスク方式を用いて約0.01ミクロン幅の強磁性超細線が作製可能になった。その超低温での抵抗測定により磁壁移動における量子効果を探索している。宮島は細線を引き伸ばし、切断直前の抵抗変化から切断部分では伝導性に量子化現象が見られることを明らかにした。高橋は超清浄雰囲気でのスパッター法によって薄膜を生成し、残留ガス圧と磁気的性質の関係が非常に奇妙な振る舞いをすることを明らかにした。すなわちCo/Cu人工格子構造においてガス圧と作製された試料の特性との関連性を明らかにした。松井は酸化物層を含むトンネルジャンクションの研究と、微細加工した基板表面に作製したGMRシステムの研究を発表した。片山はコバルトドットにおける異方性の研究をした。大越はCu/Co人工格子が示す異常な磁性を検討している。

Research Products
(23 results)

All Other

All Publications (23 results)

[Publications] T. Nagahama: "Electric Resistance of Magnetic Domain Wall in NiFe Wires with CoSm Pinning Pads"J. Appl. Phys.. (in press). (2000)
[Publications] T. Shinjo: "Study of Magnetization Reversal in Submicron Wires Using the Giant Magnetoresistance Effect"Phil. Mag.0. 80. 207-214 (2000)
[Publications] K. Shigeto: "Injection of a Magnetic Domain Wall into a Submicron Magnetic Wires"Apl. Phys. Lett.. 75. 2815-1817 (1999)
[Publications] T. Ono: "Anisotropic Structure abd Giant Magnetoresistance in Fe/Cr Multilayers on SrYiO_3 (199) Substrates with Step Terraces"Surface Sci.. 438. 341-346 (1999)
[Publications] T. Ono: "Propagation of a Magnetic Domain Wall in a Submicrometer Magnetic Wire"Phys. Rev. B.. 60. 3294-3304 (1999)
[Publications] T. Ono: "Propagation of the Magnetic Domain Wall n Submicron Magnetic Wire Investigated by Using Giant Magnetoresistance Effect"J. Appl. Phys.. 85. 6181-6184 (1999)
[Publications] K. Shigeto: "GMR effect in a Single trilayer wire with submicron width"J. Mag. Mag. Mater.. 198. 58-60 (1999)
[Publications] S. Hamada: "Spin Reorientation of the micromagnetic structure in Co/Au multilayers films with moderate perpendicular anisotropy"J. Mag. Mag. Mater.. 198. 496-499 (1999)
[Publications] T. Manago: "Appearance of ferromagnetism induced by proximity effect and exchange enhancement in multilayer consisting of antiferromagnetic NiO and paramagnetic PD"J. Phys. Soc. Jpn.. 63. 334-337 (1999)
[Publications] T. Manago: "Temperature dependence of magnetization and electrical resisteivety of weak itenerant ferromagnetic Pd in Nio/Pd multilayers"J. Phys. Soc. Jpn.. 68. 3677-3679 (1999)
[Publications] H. Miyajima: "Magnetoresistance of a ferromagnetic multiple-wire system"IEEE Trans. Mag.. 35. 3505-3508 (1999)
[Publications] T. Ono: "Dot-arrays of Co/Pt multilayers with perpendicular magnetic anisotropy"J. Mag. Mag. Matter.. 198. 225-227 (1999)
[Publications] T. Ono: "2e^2/n to e^2/n switing of quantum conductance associated with a change in nanoscale ferromagnetic domain structure"Appl. Phys. Lett.. 75. 1622-1625 (1999)
[Publications] M. Ookoshi: "Structure and unidirectional anisotrop in Co/Cu films alternated with several monolayer thicknesses"J. Mag. Mag. Mater.. 23. 1253-1256 (1999)
[Publications] M. Tsunoda: "Enhanced exchange anisotropy of NiFe/MnNi bilayers fabricated under the extremely clean sputtering process"J. Appl. Phys.. 85. 4919-4921 (1999)
[Publications] M. Konoto: "Orientation dependence of the exchange biasing in NiFe/MuNi bilayers"J. Appl. Phys.. 85. 4925-4927 (1999)
[Publications] S. Miura: "Drastic change of giant magnetoresistance of Co/Cu multilayer by decreasing residual impurities in sputtering atmosphere"J. Appl. Phys.. 85. 4463-4465 (1999)
[Publications] M. Takahashi: "Effect of Ir content and sputtering condeitions on unidirectional anisotropy of NiFe/MuIr film fabricated under the extremely ckeab soytterubg oricess"IEEE Trans. Mag.. 35. 3919-3922 (1999)
[Publications] M. Takahashi: "Extremely clean sputtering process for spin valve exchange anisotropy and spin-dependent transport"J. Mag. Mag. Mater.. 209. 65-67 (2000)
[Publications] A. K. Aoki: "Transport properties of multilayers with nanoscale structures"J. Mag. Mag. Mater.. 198. 213-215 (1999)
[Publications] M. Nyvlt: "MFM obserbation of magnetic domain structure in exchange coupled NiFe/FeRh-Ir (001) films"J. Mag. Mater.. 198. 443-446 (1999)
[Publications] M. Masaaki: "Scanning probe microscopy study of the interface rouqhness dependence of the magnetism of metallic"Appl. Surf. Sci.. 142. 527-530 (1999)
[Publications] M. Masaaki: "Giant Magnetoresistance effect of bcc-Fe/Cu multilayers"J. Mat. Sci. Tech.. 16. 186-190 (2000)

1999 Fiscal Year Annual Research Report

微小磁性体の作製とその性質

Principal Investigator

新庄 輝也 京都大学, 化学研究所, 教授 (70027043)

Research Products

[Publications] T. Nagahama: "Electric Resistance of Magnetic Domain Wall in NiFe Wires with CoSm Pinning Pads"J. Appl. Phys.. (in press). (2000)

[Publications] T. Shinjo: "Study of Magnetization Reversal in Submicron Wires Using the Giant Magnetoresistance Effect"Phil. Mag.0. 80. 207-214 (2000)

[Publications] K. Shigeto: "Injection of a Magnetic Domain Wall into a Submicron Magnetic Wires"Apl. Phys. Lett.. 75. 2815-1817 (1999)

[Publications] T. Ono: "Anisotropic Structure abd Giant Magnetoresistance in Fe/Cr Multilayers on SrYiO_3 (199) Substrates with Step Terraces"Surface Sci.. 438. 341-346 (1999)

[Publications] T. Ono: "Propagation of a Magnetic Domain Wall in a Submicrometer Magnetic Wire"Phys. Rev. B.. 60. 3294-3304 (1999)

[Publications] T. Ono: "Propagation of the Magnetic Domain Wall n Submicron Magnetic Wire Investigated by Using Giant Magnetoresistance Effect"J. Appl. Phys.. 85. 6181-6184 (1999)

[Publications] K. Shigeto: "GMR effect in a Single trilayer wire with submicron width"J. Mag. Mag. Mater.. 198. 58-60 (1999)

[Publications] S. Hamada: "Spin Reorientation of the micromagnetic structure in Co/Au multilayers films with moderate perpendicular anisotropy"J. Mag. Mag. Mater.. 198. 496-499 (1999)

[Publications] T. Manago: "Appearance of ferromagnetism induced by proximity effect and exchange enhancement in multilayer consisting of antiferromagnetic NiO and paramagnetic PD"J. Phys. Soc. Jpn.. 63. 334-337 (1999)

[Publications] T. Manago: "Temperature dependence of magnetization and electrical resisteivety of weak itenerant ferromagnetic Pd in Nio/Pd multilayers"J. Phys. Soc. Jpn.. 68. 3677-3679 (1999)

[Publications] H. Miyajima: "Magnetoresistance of a ferromagnetic multiple-wire system"IEEE Trans. Mag.. 35. 3505-3508 (1999)

[Publications] T. Ono: "Dot-arrays of Co/Pt multilayers with perpendicular magnetic anisotropy"J. Mag. Mag. Matter.. 198. 225-227 (1999)

[Publications] T. Ono: "2e^2/n to e^2/n switing of quantum conductance associated with a change in nanoscale ferromagnetic domain structure"Appl. Phys. Lett.. 75. 1622-1625 (1999)

[Publications] M. Ookoshi: "Structure and unidirectional anisotrop in Co/Cu films alternated with several monolayer thicknesses"J. Mag. Mag. Mater.. 23. 1253-1256 (1999)

[Publications] M. Tsunoda: "Enhanced exchange anisotropy of NiFe/MnNi bilayers fabricated under the extremely clean sputtering process"J. Appl. Phys.. 85. 4919-4921 (1999)

[Publications] M. Konoto: "Orientation dependence of the exchange biasing in NiFe/MuNi bilayers"J. Appl. Phys.. 85. 4925-4927 (1999)

[Publications] S. Miura: "Drastic change of giant magnetoresistance of Co/Cu multilayer by decreasing residual impurities in sputtering atmosphere"J. Appl. Phys.. 85. 4463-4465 (1999)

[Publications] M. Takahashi: "Effect of Ir content and sputtering condeitions on unidirectional anisotropy of NiFe/MuIr film fabricated under the extremely ckeab soytterubg oricess"IEEE Trans. Mag.. 35. 3919-3922 (1999)

[Publications] M. Takahashi: "Extremely clean sputtering process for spin valve exchange anisotropy and spin-dependent transport"J. Mag. Mag. Mater.. 209. 65-67 (2000)

[Publications] A. K. Aoki: "Transport properties of multilayers with nanoscale structures"J. Mag. Mag. Mater.. 198. 213-215 (1999)

[Publications] M. Nyvlt: "MFM obserbation of magnetic domain structure in exchange coupled NiFe/FeRh-Ir (001) films"J. Mag. Mater.. 198. 443-446 (1999)

[Publications] M. Masaaki: "Scanning probe microscopy study of the interface rouqhness dependence of the magnetism of metallic"Appl. Surf. Sci.. 142. 527-530 (1999)

[Publications] M. Masaaki: "Giant Magnetoresistance effect of bcc-Fe/Cu multilayers"J. Mat. Sci. Tech.. 16. 186-190 (2000)

新庄輝也京都大学, 化学研究所, 教授 (70027043)