Updated on 2022/10/26

写真a

 
OSHIMA Daiki
 
Organization
Graduate School of Engineering Electronics 2 Assistant Professor
Graduate School
Graduate School of Engineering
Undergraduate School
School of Engineering Electrical Engineering, Electronics, and Information Engineering
Title
Assistant Professor

Degree 1

  1. 博士(工学) ( 2014.3   名古屋大学 ) 

Research Interests 2

  1. スピンデバイス

  2. 磁気記録

Professional Memberships 2

  1. The Institute of Electrical and Electronics Engineers

  2. 日本磁気学会

Awards 1

  1. 電気学会 基礎・材料・共通部門 平成28年優秀論文発表賞

    2016   電気学会   MnGa膜を用いたイオン照射型ビットパターン媒体の高密度化の検討

    大島大輝

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

 

Papers 32

  1. Magneto-optical property and magnetic anisotropy of (100) oriented R0.5Bi2.5Fe5O12 (R = Eu, Sm, and Pr) thin films prepared by metal–organic decomposition Reviewed

    R. Urakawa, W. Asano, M. Nishikawa, M. Kawahara, T. Nishi, D. Oshima, T. Kato, and T. Ishibashi

    AIP Advances   Vol. 12   page: 095322   2022.9

  2. Electric-Field Modulation of Perpendicular Magnetic Anisotropy and Damping Constant in MgO/Co/Pt Trilayers

    Sakoguchi A., Oshima D., Iwata S., Kato T.

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 58 ( 2 )   2022.2

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    Language:Japanese  

    DOI: 10.1109/TMAG.2021.3083078

    Web of Science

  3. Effect of substrate temperature on plasma-enhanced self-assembling formation of high-density FePt nanodots

    Honda Shunsuke, Makihara Katsunori, Taoka Noriyuki, Furuhata Hiroshi, Ohta Akio, Oshima Daiki, Kato Takeshi, Miyazaki Seiichi

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 61 ( SA )   2022.1

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    Language:Japanese  

    DOI: 10.35848/1347-4065/ac2036

    Web of Science

  4. Enhancement of spin-orbit torques by change in uniaxial in-plane magnetic anisotropy of Py/Pt bilayers on single crystal 128 degrees Y-Cut LiNbO3 substrate Reviewed

    Ito Masayoshi, Yamaguchi Akinobu, Oshima Daiki, Kato Takeshi, Shima Mutsuhiro, Yamada Keisuke

    APPLIED PHYSICS LETTERS   Vol. 119 ( 15 )   2021.10

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    Language:Japanese  

    DOI: 10.1063/5.0063207

    Web of Science

  5. Crystal Structure and Magnetic and Magneto-optical Properties of CoPt, MnPt3, CrPt3, MnAl and MnGa Films with Ordered Phase and Their Bit-patterned Media Invited Reviewed

    S. Iwata, T. Kato, D. Oshima

    Journal of the magnetics society of Japan   Vol. 45 ( 5 ) page: 118 - 124   2021.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.3379/msjmag.2109R002

    DOI: doi.org/10.3379/msjmag.2109R002

  6. Topotactic crystal structure transformation from spinet ferrite to wustite in epitaxial Fe3O4 films via Kr ion irradiation Reviewed

    Liu Yang, Hisamatsu Yuki, Sharmin Sonia, Oshima Daiki, Iwata Satoshi, Kato Takeshi, Sekiba Daiichiro, Kita Eiji, Yanagihara Hideto

    JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A   Vol. 39 ( 3 )   2021.5

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    Language:Japanese  

    DOI: 10.1116/6.0000885

    Web of Science

  7. Progress on efficient current-induced magnetization switching

    Kato Takeshi, Iwata Satoshi, Oshima Daiki

    ELECTRICAL ENGINEERING IN JAPAN   Vol. 212 ( 1-4 ) page: 3 - 10   2020.9

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    Language:Japanese  

    DOI: 10.1002/eej.23278

    Web of Science

  8. Spin orbit torques in ferrimagnetic GdFeCo with various compositions Reviewed

    Kawakami Keisuke, Kato Takeshi, Oshima Daiki, Iwata Satoshi

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 59   2020.4

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    Language:Japanese  

    DOI: 10.7567/1347-4065/ab51b5

    Web of Science

  9. Highly (001) oriented MnAl thin film fabricated on CoGa buffer layer Reviewed

    Oshima Daiki, Kato Takeshi, Iwata Satoshi

    AIP ADVANCES   Vol. 10 ( 2 )   2020.2

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    Authorship:Lead author, Corresponding author   Language:Japanese  

    DOI: 10.1063/1.5130452

    Web of Science

  10. Spin transfer torque switching of hybrid memory layers with low Curie temperature CoPd/Pd multilayers Reviewed

    Zhao Wangzhen, Kimura Takumi, Kato Takeshi, Oshima Daiki, Sonobe Yoshiaki, Takahashi Shigeki, Iwata Satoshi

    JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   Vol. 493   2020.1

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  11. Patterned arrays of assembled nanoparticles prepared by interfacial assembly and femtosecond laser fabrication

    Jiang Chengpeng, Oshima Daiki, Iwata Satoshi, Pong Philip W. T., Kato Takeshi

    JOURNAL OF NANOPARTICLE RESEARCH   Vol. 22 ( 1 )   2019.12

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    Language:Japanese  

    DOI: 10.1007/s11051-019-4718-8

    Web of Science

  12. MnGa (001)-Textured Film Fabricated on Thermally Oxidized Si Substrate for Application to Ion Beam Bit Patterned Media

    Ishikawa Toru, Miwa Yoshitsugu, Oshima Daiki, Kato Takeshi, Iwata Satoshi

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 55 ( 7 )   2019.7

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    Language:Japanese  

    DOI: 10.1109/TMAG.2018.2889499

    Web of Science

  13. Ion Irradiation for Planar Patterning of Magnetic Materials

    Kato Takeshi, Oshima Daiki, Iwata Satoshi

    CRYSTALS   Vol. 9 ( 1 )   2019.1

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    Language:Japanese  

    DOI: 10.3390/cryst9010027

    Web of Science

  14. Variation of Magnetization Dynamics of Co/Ni Multilayer by Capturing Magnetic Nanoparticles Reviewed

    Otaki Y., Kato T., Okamoto S., Kikuchi N., Oshima D., Iwata S., Kitakami O.

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 54 ( 11 )   2018.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TMAG.2018.2832660

    Web of Science

  15. Hybrid Memory Layer With Low Curie Temperature CoPd/Pd Multilayer for High-Density Magnetic Random-Access Memory Cells Reviewed

    Zhao W., Dong X., Kimura T., Kato T., Oshima D., Sonobe Y., Kawato Y., Iwata S.

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 54 ( 11 )   2018.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TMAG.2018.2828138

    Web of Science

  16. Spin transfer torque switching of Co/Pd multilayers and Gilbert damping of Co-based multilayers

    Kimura Takumi, Dong Xiayin, Adachi Kanta, Oshima Daiki, Kato Takeshi, Sonobe Yoshiaki, Okamoto Satoshi, Kikuchi Nobuaki, Kawato Yoshiaki, Kitakami Osamu, Iwata Satoshi

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 57 ( 9 )   2018.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.7567/JJAP.57.09TD01

    Web of Science

  17. Femtosecond resonant magneto-optical Kerr effect measurement on an ultrathin magnetic film in a soft X-ray free electron laser Reviewed

    Yamamoto Shingo, Kubota Yuya, Yamamoto Kohei, Takahashi Yoshinobu, Maruyama Kohei, Suzuki Yuta, Hobara Rei, Fujisawa Masami, Oshima Daiki, Owada Shigeki, Togashi Tadashi, Tono Kensuke, Yabashi Makina, Hirata Yasuyuki, Yamamoto Susumu, Kotsugi Masato, Wadati Hiroki, Kato Takeshi, Iwata Satoshi, Shin Shik, Matsuda Iwao

    JAPANESE JOURNAL OF APPLIED PHYSICS   Vol. 57 ( 9 )   2018.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.7567/JJAP.57.09TD02

    Web of Science

  18. Spin-valve giant magneto-resistance film with magnetostrictive FeSiB amorphous layer and its application to strain sensors Reviewed

    Hashimoto Y., Yamamoto N., Kato T., Oshima D., Iwata S.

    JOURNAL OF APPLIED PHYSICS   Vol. 123 ( 11 )   2018.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1063/1.5018467

    Web of Science

  19. Switching Field Distribution of MnGa Bit Patterned Film Fabricated by Ion Beam Irradiation Reviewed

    Oshima D., Kato T., Iwata S.

    IEEE TRANSACTIONS ON MAGNETICS   Vol. 54 ( 2 )   2018.2

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TMAG.2017.2733765

    Web of Science

  20. Hybrid memory layer with low Curie temperature CoPd/Pd multilayer for high-density magnetic random access memory cells

    Zhao W., Kimura T., Kato T., Oshima D., Sonobe Y., Kawato Y., Iwata S.

    2018 IEEE INTERNATIONAL MAGNETIC CONFERENCE (INTERMAG)     2018

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    Language:Japanese  

    Web of Science

  21. Nano spin-diodes using FePt-NDs with huge on/off current ratio at room temperature Reviewed

    K. Makihara, T. Kato, Y. Kabeya, Y. Mitsuyuki, A. Ohta, D. Oshima, S. Iwata, Y. Darma, M. Ikeda, S. Miyazaki

    Scientific Reports   Vol. 6   page: 33409   2016.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/srep33409

  22. Ferromagnetic Resonance of a Single Magnetochiral Metamolecule of Permalloy Reviewed

    T. Kodama, S. Tomita, T. Kato, D. Oshima, S. Iwata, S. Okamoto, N. Kikuchi, O. Kitakami, N. Hosoito, H. Yanagi

    Physical Review Applied   Vol. 6   page: 024016-1-9   2016.8

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    Language:English   Publishing type:Research paper (scientific journal)  

  23. Effective Damping Constant and Current Induced Magnetization Switching of GdFeCo/TbFe Exchange-Coupled Bilayers Reviewed

    T. Higashide, B. Dai, T. Kato, D. Oshima, S. Iwata

      Vol. 7   page: 3505605   2016.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/LMAG.2016.2595502

  24. Nanoscale patterning of CrPt3 magnetic thin films by using ion beam irradiation Reviewed

    E. Suharyadi, D. Oshima, T. Kato, S. Iwata

    Results in Physics   Vol. 6   page: 186-188   2016.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.rinp.2016.03.010

  25. Ion irradiation induced magnetic transition of MnGa alloy films studied by X-ray magnetic circular dichroism and low-temperature hysteresis loops Reviewed

    D. Oshima, M. Tanimoto, T. Kato, Y. Fujiwara, T. Nakamura, Y. Kotani, S. Tsunashima, S. Iwata

    IEEE Transactions on Magnetics   Vol. 52 ( 7 ) page: 3201804-1-4   2016.2

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TMAG.2016.2527050

  26. Structure and Magnetic Properties of (001) Oriented CoPt-Ag and CoPd-Ag Alloy Films Reviewed

    T. Nagata, Y. Tokuoka, T. Kato, D. Oshima, S. Iwata

    Journal of Magnetics Society of Japan   Vol. 40 ( 1 ) page: 13-17   2016.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.3379/msjmag.1512R003

  27. Anomalous structural behavior in the metamagnetic transition of FeRh thin films from a local viewpoint Reviewed

    Y. Wakisaka, Y. Uemura, T. Yokoyama, H. Asakura, H. Morimoto, M. Tabuchi, D. Oshima, T. Kato, S. Iwata

    Physical Review B   Vol. 92   page: 184408   2015.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1103/PhysRevB.92.184408

  28. Magnetization control for bit pattern formation of spinel ferromagnetic oxides by Kr ion implantation Reviewed

    E. Kita, K. Z. Suzuki, Y. Liu, Y. Utsumi, J. Morishita, D. Oshima, T. Kato, T. Niizeki, K. Mibu, H. Yanagihara

    Journal of Applied Physics   Vol. 115   page: 17B907   2014

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    Language:English   Publishing type:Research paper (scientific journal)  

  29. Control of magnetic properties of MnGa films by Kr+ ion irradiation for application to bit patterned media Reviewed

    D. Oshima, T. Kato, S. Iwata, S. Tsunashima

    IEEE Transactions on Mgnetics   Vol. 49 ( 7 ) page: 3608-3611   2013

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    Language:English   Publishing type:Research paper (scientific journal)  

  30. Observation of ferri-nonmagnetic boundary in CrPt3 line-and-space patterned media using a dark-field transmission electron microscope Reviewed

    D. Oshima, E. Suharyadi, T. Kato, S. Iwata

    Journal of Magnetism and Magnetic Materials   Vol. 324   page: 1617-1621   2012

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  31. Switching field distribution of planar-patterned CrPt3 nanodots fabricated by ion irradiation Reviewed

    E. Suharyadi, D. Oshima, T. Kato, S. Iwata

    Journal of Applied Physics   Vol. 109   page: 07B771   2011

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    Language:English   Publishing type:Research paper (scientific journal)  

  32. Fabrication of L12-CrPt3 Alloy Using Rapid Thermal Annealing for Planar Bit Patterned Media Reviewed

    T. Kato, D. Oshima, Y. Yamauchi, S. Iwata, S. Tsunashima

    IEEE Transactions on Magnetics   Vol. 46 ( 6 ) page: 1671-1674   2010

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    Language:English   Publishing type:Research paper (scientific journal)  

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Presentations 29

  1. 高TC/低TCハイブリッド層のスピン移行トルク磁化反転における界面高TC層の影響

    趙望臻,加藤剛志,大島大輝,岩田聡

    マグネティックス研究会  2022.3.4 

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    Event date: 2022.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  2. GdFeCo/Cu/FeCo三層膜の超短パルス光誘起磁化ダイナミクス

    瀬口和也,大島大輝,加藤剛志

    IEEE Magnetics Society名古屋支部若手研究会  2022.2.2 

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (general)  

  3. LiNbO3単結晶基板上のPy/Pt薄膜における面内一軸磁気異方性とスピン軌道トルクの相関解明

    伊藤将慶,山口明啓,大島大輝,加藤剛志,嶋睦宏,山田啓介

    IEEE Magnetics Society名古屋支部若手研究会  2022.2.2 

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (general)  

  4. Effect of high TC interface layer in high TC/ low TC hybrid memory layer on thermally assisted spin-transfer-torque switching International conference

    W. Zhao, T. Kato, D. Oshima, S. Iwata

    The 15th Joint MMM-INTERMAG Conference  2022.1  IEEE

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    Event date: 2022.1

    Language:English   Presentation type:Poster presentation  

  5. β-Mn型CoZnMnエピタキシャル薄膜の作製

    大島大輝,三橋良祐,五十嵐信行,加藤剛志,長尾全寛

    マグネティックス研究会  2021.12.2  電気学会

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    Event date: 2021.12

    Language:Japanese   Presentation type:Oral presentation (general)  

  6. Fabrication of epitaxially grown β-Mn type CoZnMn film International conference

    D. Oshima, M. Kawai, R. Mitsuhashi, S. Hirata, N. Ikarashi, T. Kato, M. Nagao

    International Confernce on Materials and Systems for Sustainability 2021  2021.11.5 

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    Event date: 2021.11

    Language:English   Presentation type:Poster presentation  

  7. Enhancement of spin-orbit torques using change of uniaxial in-plane magnetic anisotropy in Py/Pt bilayers on a single crystal Y-Cut 128° LiNbO3 substrate International conference

    M. Ito, A. Yamaguchi, D. Oshima, T. Kato, M. Shima, K. Yamada

    International Confernce on Materials and Systems for Sustainability 2021  2021.11.5  IMaSS

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    Event date: 2021.11

    Language:English   Presentation type:Poster presentation  

    Venue:Virtual  

  8. Magnetic anisotropy of highly bismuth-substituted rare-earth (Y, Pr, Nd, Sm and Er) iron garnet thin films International conference

    T. Ishibashi, R. Urakawa, M. Nishikawa, T. Nishi, D. Oshima, T. Kato

    International Confernce on Materials and Systems for Sustainability 2021  2021.11.5  IMaSS

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    Event date: 2021.11

    Language:English   Presentation type:Poster presentation  

  9. The study of interface layer in hybrid memory layer for thermally assisted STT-MRAM cells International conference

    W. Zhao, T. Kato, D. Oshima, S. Iwata

    International Confernce on Materials and Systems for Sustainability 2021  2021.11.5  IMaSS

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    Event date: 2021.11

    Language:English   Presentation type:Poster presentation  

  10. 高TC/低TCハイブリッド層を用いた熱アシストSTT磁化反転における界面高TC層の影響

    趙望臻,加藤剛志,大島大輝,岩田聡

    第45回日本磁気学会学術講演会  2021.9.1  日本磁気学会

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    Event date: 2021.8 - 2021.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  11. LiNbO3単結晶基板上の2層構造Py/Ptにおける面内一軸磁気異方性によるスピン軌道トルクの変化

    伊藤将慶,山口明啓,大島大輝,加藤剛志,嶋睦宏,山田啓介

    第45回日本磁気学会学術講演会  2021.9.1  日本磁気学会

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    Event date: 2021.8 - 2021.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  12. グラニュラー薄膜を用いたひずみセンサの開発

    上野駿平,天満光佑,上部智也,藤原裕司,大島大輝,加藤剛志,神保睦子

    第45回日本磁気学会学術講演会  2021.9.2  日本磁気学会

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    Event date: 2021.8 - 2021.9

    Language:Japanese   Presentation type:Oral presentation (general)  

  13. Electric-field modulation of perpendicular magnetic anisotropy and damping constant in MgO/Co/Pt trilayers International conference

    A. Sakoguchi, T. Kato, D. Oshima, S. Iwata

    INTERMAG 2021 Conference  2021.4.29  IEEE

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    Event date: 2021.4

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Virtual  

  14. ビットパターン媒体に用いるSi基板上MnGa (001)配向膜の作製

    三輪佳嗣,石川徹,大島大輝,加藤剛志,岩田聡

    第42回日本磁気学会学術講演会 

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    Event date: 2018.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  15. 低キュリー温度CoPd/Pd系多層膜を用いたMRAM用交換結合ハイブリッドメモリ層

    趙望臻,木村匠,董夏茵,大島大輝,加藤剛志,園部義明,川戸良昭,岩田聡

    第42回日本磁気学会学術講演会 

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    Event date: 2018.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  16. Co/Pd多層膜のスピン注入磁化反転臨界電流の層厚比依存性

    趙望臻,木村匠,大島大輝,加藤剛志,園部義明,川戸良昭,岩田聡

    第42回日本磁気学会学術講演会 

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    Event date: 2018.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  17. CoGa下地層を用いた極薄L10-MnGa膜の磁気パターニング

    堀江祐貴,三輪佳嗣,大島大輝,加藤剛志,岩田聡

    第42回日本磁気学会学術講演会 

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    Event date: 2018.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  18. Fe3O4 / Cr 多層膜における垂直磁気異方性

    大島大輝,加藤剛志,岩田聡

    第42回日本磁気学会学術講演会 

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    Event date: 2018.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  19. Ion beam patterning of ultrathin L10-MnGa (001) film grown on CoGa buffer layer International conference

    Y. Horie, D. Oshima, T. Kato, S. Iwata

    IEEE International Magnetics Conference 2018 

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    Event date: 2018.4

    Language:English   Presentation type:Poster presentation  

    Country:Singapore  

  20. Scanning X-ray magnetic circular dichroism observation of magnetic state of ion-irradiation bit patterned L10-MnGa films International conference

    T. Ishikawa, K. Fukuta, D. Oshima, T. Kato, T. Nakamura, Y. Kotani, K. Toyoki, S. Iwata

    International Conference on Materials and Systems for Sustainability 

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    Event date: 2017.9 - 2017.10

    Language:English   Presentation type:Poster presentation  

    Country:Japan  

  21. 走査型XMCD顕微鏡によるイオン照射型L10-MnGaビットパターン膜の局所的磁気状態の評価

    石川徹,福田憲吾,大島大輝,加藤剛志,中村哲也,小谷佳範,豊木研太郎,岩田聡

    第41回日本磁気学会学術講演会 

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    Event date: 2017.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  22. イオン照射により作製したMnGaビットパターン膜のFORC解析

    大島大輝,加藤剛志,岩田聡

    第41回日本磁気学会学術講演会 

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    Event date: 2017.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  23. Ion Beam Bit Patterned Media Using MnGa Alloy Films Invited International conference

    D. Oshima, T. Kato, S. Iwata

    The 28th Magnetic Recording Conference 

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    Event date: 2017.8

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:Tsukuba, Japan   Country:Japan  

  24. First order reversal curve diagram analysis of ion irradiated bit patterned MnGa film International conference

    D. Oshima, T. Kato, S. Iwata

    IEEE International Magnetics Conference 2017 

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    Event date: 2017.4

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Dublin, Ireland   Country:Japan  

  25. Ion irradiation induced magnetic transition of MnGa alloy films studied by X-ray magnetic circular dichroism and low-temperature hysteresis loops International conference

    D. Oshima, M. Tanimoto, T. Kato, Y. Fujiwara, T. Nakamura, Y. Kotani, S. Tsunashima, S. Iwata

    2016 Joint MMM-Intermag Conference 

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    Event date: 2016.1

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  26. Control of Magnetic Inactivation Layer Thickness in MnGa Film by Kr Ion Irradiation International conference

    D. Oshima, T. Kato, S. Takahashi, Y. Sonobe, S. Iwata, S. Tsunashima

    20th International Conference on Magnetism 

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    Event date: 2015.7

    Language:English   Presentation type:Poster presentation  

    Country:Japan  

  27. (001) Oriented MnGa Film Grown on Si Substrate for Ion Beam Patterned Media International conference

    D. Oshima, T. Negoro, T. Kato, S. Iwata, S. Tsunashima

    20th International Conference on Magnetism 

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    Event date: 2015.7

    Language:English   Presentation type:Poster presentation  

    Country:Japan  

  28. Anisotropic X-ray magnetic circular dichroism spectra of (001) oriented L10-MnGa film International conference

    D. Oshima, M. Tanimoto, T. Kato, Y. Fujiwara, T. Nakamura, Y. Kotani, S. Tsunashima, S. Iwata

    IEEE International Magnetics Conference 2015 

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    Event date: 2015.5

    Language:English   Presentation type:Poster presentation  

    Country:Japan  

  29. Magnetic circular dichroism measurement of ion irradiated MnGa films International conference

    D. Oshima, M. Tanimoto, T. Kato, Y. Fujiwara, T. Nakamura, Y. Kotani, S. Tsunashima, S. Iwata

    IEEE International Magnetics Conference 2014 

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    Event date: 2014.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

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KAKENHI (Grants-in-Aid for Scientific Research) 7

  1. 高密度スキルミオン流の流体力学的輸送特性の研究

    Grant number:21H01029  2021.4 - 2024.3

    科学研究費助成事業  基盤研究(B)

    長尾 全寛, 大島 大輝

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    磁気スキルミオンは安定な粒子として振る舞い、超低密度電流駆動を示すことからスキルミオンを情報キャリアとして利用する応用的価値に注目が集まっている。特に、スキルミオン間相互作用が存在する高密度スキルミオンの集団的運動は、非圧縮性トポロジカル粒子流という分野横断的な舞台を提供する可能性があり、デバイス応用を目指す上でもその解明は重要である。本研究では、高密度スキルミオンの集団的運動の特性を流体力学的アプローチによって解明する。特に、高密度スキルミオンの集団的運動はスキルミオン間相互作用に起因するスキルミオン粘性流の発現が見込まれ、超高速駆動やホール粘性などの新規輸送特性の観測が期待される。

  2. 空間対称性の破れの制御によるスピン軌道トルクの増強と3次元メモリへの展開

    Grant number:20H02182  2020.4 - 2023.3

    科学研究費助成事業  基盤研究(B)

    加藤 剛志, 大島 大輝

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    Authorship:Coinvestigator(s) 

    スピン軌道トルク(SOT)磁化反転は磁性層に隣接する非磁性層に電流を流すことで磁化反転を行なうもので,既存のスピン移行トルク(STT)磁化反転に比べ1/5程度の消費電力で10倍高速に磁化反転ができると考えら,今後のSociety 5.0を支える大容量磁気ランダムアクセスメモリ(MRAM)への応用研究が進められている.本研究は磁性材料に空間反転対称性の破れを人工的に導入することで,SOT磁化反転の高効率化を図るとともに,これを利用した3次元メモリの原理実証を行なう.
    本年度は重希土類であるGdと遷移金属であるFeCoの合金およびそれらの多層膜をマグネトロンスパッタ法により作製し,その磁気特性の評価を行うとともに,5 um-10 um幅の細線状に微細加工し,スピン軌道トルクおよびスピン軌道トルク磁化反転の膜構成依存性,温度依存性を調べた.まず,GdFeCo合金のスピン軌道トルクの温度依存性,膜厚依存性を評価した.GdFeCoのフィールドライクトルク(スピン軌道トルクの1つ)は磁化補償温度を挟んで符号が反転することを確認し,このフィールドライクトルクの符号により磁化反転のしやすさが変化することが分かった.また,GdFeCoのスピン軌道トルクは膜厚の増加に対して減少する傾向が得られたが,単調に膜厚の逆数に比例しないことが分かった.これは,GdFeCo膜は膜厚方向に均一ではなく,空間反転対称性が破れていることを反映していると考えられ,バルクジャロシンスキー守谷(DMI)相互作用が大きくなっている可能性を示唆する結果が得られた.次にGd(x)/FeCo(1-x)多層膜においてxを変化させ,そのスピン軌道トルクの変化を調べた.作製したGd/FeCo多層膜はx = 0.5-0.55 nmで磁化補償となることを確認され,Gd/FeCo多層膜のスピン軌道トルクの等価磁場は磁化補償となる膜構成において増加することが確認された.この傾向はGdFeCo合金と同様であり,膜厚を精密に制御したGd/FeCo多層膜が作製できてることが確認された.
    本年度,新型感染症の拡大により,本学の警戒カテゴリーが上昇し,学生の入構制限,研究活動の制限などにより,研究進捗が2ヶ月程度遅れた.これにより本年度予定していた膜厚方向に対称性の破れた希土類/遷移金属多層膜の作製まで検討を進めることができなかったが,現在は通常通りの研究活動を行うことができる状態に戻っており,今後十分進捗の遅れをカバーできると考えている.また,感染症拡大のため,磁界中プローバへの磁区観察ユニットの納入も当初予定に比べ遅れたため,磁区観察によるジャロシンスキー守谷相互作用の評価もやや遅れているが,こちらも今後十分進捗遅れをカバーできると考えられる.
    Gd/FeCo系多層膜の膜厚方向に構造変調を加えることで人工的に空間反転対称性を破った試料を作製し,ジャロシンスキー守谷(DMI)相互作用を計測する.Gd/FeCo系多層膜の膜構造とDMIの相関を明らかにし,空間反転対称性の破れによるDMI増強を確認する.また,空間反転対称性の破れとGd/FeCo多層膜の角運動量補償によるスピン軌道トルクの増強を試みる.具体的には,複数の組成勾配Gd/FeCo系多層膜を積層した 交換結合膜とすることで,角運動量補償,DMI増強を同時に達成し,それによるスピン軌道トルクの増強を調べる.さらに,Gd/FeCo系多層膜またはより微細加工が容易なCo/Pd系多層膜を含む3次元メモリ構造を作製し,スピン軌道トルク磁化反転とスピン移行トルクによる情報伝達という3次元メモリの原理実証を進める.

  3. Fabrication of artificial multilayer using ferromagnetic oxide and its application to voltage-driven memory devices

    Grant number:19K15044  2019.4 - 2021.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

    Oshima Daiki

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    Authorship:Principal investigator 

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

    For application to voltage-driven magnetic memories, ferromagnetic-oxide / ferromagnetic-metal / nonmagnetic metal repetition layer structure was fabricated by magnetron sputtering method, and the magnetic property and the crystal structure of the samples were evaluated. Zn ferrite, used as a ferromagnetic-oxide, was epitaxially grown on ferromagnetic FeCo / nonmagnetic W buffer layers. Perpendicular magnetic anisotropy, which is important for memory applications, was confirmed in the repetition multilayer. There is the possibility that the proposed structure is available in the magnetic memories.

  4. Magnetization switching by spin current induced by ultra short pulse laser

    Grant number:17K18878  2017.6 - 2019.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Research (Exploratory)

    Kato Takeshi

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    In order to observe spin current generation by the ultra short pulse laser and the magnetization switching by the spin current, two experiments, 1) spin current injection to Au from 3d transition metal Fe and 2) magnetization switching of GdFeCo by injecting the spin current, were carried out. Fe thickness dependence of the damping constant of Fe showed the Au layer has useful properties as a spin current conductor. When the spin current injected to GdFeCo, the moment of GdFeCo feels large equivalent magnetic field around the compensation composition. Moreover, it was found that the injected spin current exerts a torque to only FeCo moment.

  5. Local magnetization control using spin Hall effect and its application to GMR magnetic sensors

    Grant number:17H03249  2017.4 - 2020.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Iwata Satoshi

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    In this research project, we have developed strain-sensor using giant magnetoresistance effect, where inverse magneto-striction effect is applied to the magnetic free layer in a spin valve structure. In order to avoid from influence of magnetic stray field, we employ sinusoidal signal detection method, where the magnetization direction of the magnetic free layer was modulated by alternative magnetic field by flowing AC current through Al strip line formed on GMR element. In next stage, we have investigated magnetization control by spin-Hall effect. The sensor device is composed from Ta/FeCo layer for producing spin current, a magnetoresistive spin-valve element and anti-ferromagneic NiO layer which magnetically connects Ta/FeCo and spin-valve layers. In this device, magnetization reversal by spin Hall effect was observed.

  6. Control of spin dynamics by electric field and electric-field-assisted spin Hall switching

    Grant number:16H04328  2016.4 - 2019.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Kato Takeshi

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    Spin Hall switching is considered as a promising way of the next generation writing scheme of the magnetic random access memories. This study focused on the effect of the applied electric field on the spin Hall switching of Co and Fe ultrathin films, where the electric field was applied thorough HfO2/MgO insulation layer. Moreover, the effect of the electric field on the spin dynamics was also studied. The coercivity and current density of the spin Hall switching were modified by the electric field as 43 %/(V/m) and 20 %/(V/m), respectively. The modifications of the coercivity and the current density of the spin Hall switching by the electric field were found to be sensitive to the deposition condition of the insulation layer.

  7. Control of magnonic crystal by voltage

    Grant number:16K18091  2016.4 - 2018.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    OSHIMA Daiki

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    Authorship:Principal investigator 

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

    Development of materials was carried out in order to control spin wave by using periodic nano-sized electrodes. First, voltage was applied to the fabricated samples, however, the voltage effect was not obtained. Thinning the sample was tried because it was effective to obtain a voltage effect. As a result, thinning the sample without degrading the property of the sample was successful. In addition, a multilayered structure of ferromagnetic insulator / ferromagnetic metal / nonmagnetic metal was suggested as a new system for voltage application, and the prototype of the structure was fabricated. It was found that the fabricated structure had a perpendicular magnetic anisotropy. In the future, micro-fabrication process will be optimized and the experiment for voltage application will be carried out.

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Teaching Experience (On-campus) 4

  1. 電気磁気学基礎演習

    2015

  2. 電気電子工学実験

    2015

  3. 電気電子工学実験

    2014

  4. 電気磁気学基礎演習

    2014