Details of the Researcher

PHOTO

Tomoo Nakai
Section
Graduate School of Engineering
Job title
Assistant Professor
e-Rad No.
80270817
Researcher ID
PEV-9913-2025

Research History 5

  • 2025/04 - Present
    東北大学大学院工学研究科 ファインメカニクス専攻　助教

  • 1999/04 - 2025/03
    宮城県産業技術総合センター

  • 1996/04 - 1999/03
    宮城県工業技術センター

  • 1994/04 - 1996/03
    東北大学工学部機械知能工学科　助手

  • 1989/04 - 1994/03
    宮城県工業技術センター

Education 2

  • Tohoku University　Graduate School of Engineering

    1988/04 - 1989/03

  • Tohoku University

    - 1988/03

Professional Memberships 4

  • The Magnetics Society of Japan

  • The Institute of Electrical Engineers of Japan

  • The Japanese Society for Non-Destructive Inspection

  • 日本機械学会

Research Interests 4

  • センサ

  • 薄膜

  • sensor

  • thin film

Research Areas 3

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Machine materials and mechanics /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electric/electronic material engineering /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electronic devices and equipment /

Papers 46

  1. Analysis of Magnetic Domain Transition for Magnetostrictive Co-Nb-Zr thin film strips with inclined uniaxial easy-axis Peer-reviewed

    Tomoo Nakai

    IEEE Transactions on Magnetics　1-6　2026/06

    DOI： 10.1109/TMAG.2026.3698404 　

  2. Influence of Processing Method on the Multiple Resonance of Amorphous Co84.5Nb7.5Zr8 Thin Films Peer-reviewed

    Tomoo Nakai

    SPIN　16　(1&2)　2650003-1-2650003-14　2026/03/10

    DOI： 10.1142/S2010324726500037 　

  3. Influence of distributed surface-normal magnetic field on the permeability of magnetostrictive Co-Nb-Zr thin-film strips Peer-reviewed

    Tomoo Nakai

    Materials Today Communications　50　114384　2026/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.mtcomm.2025.114384 　

    ISSN： 2352-4928

  4. Relationship of Magnetic Domain and Permeability for Clustered Soft Magnetic Narrow Strips with In-Plane Inclined Magnetization Easy Axis on Distributed Magnetic Field Peer-reviewed

    Tomoo Nakai

    Sensors　24　(2)　706　2024/01/22

    Publisher: MDPI AG

    DOI： 10.3390/s24020706 　

    eISSN： 1424-8220

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    A unique functionality was reported for a thin-film soft magnetic strip with a certain angle of inclined magnetic anisotropy. It can switch magnetic domain by applying a surface normal field with a certain distribution on the element. The domain switches between a single domain and a multi-domain. Our previous study shows that this phenomenon appears even in the case of the adjacent configuration of multiple narrow strips. It was also reported that the magnetic permeability for the alternating current (AC) magnetic field changes drastically in the frequency range from 10 kHz to 10 MHz as a function of the strength of the distributed magnetic field. In this paper, the correspondence of AC permeability and the magnetic domain as a function of the intensity of the distributed field is investigated. It was confirmed that the extension of the area of the Landau–Lifshitz-like multi-domain on the clustered narrow strips was observed as a function of the intensity of the distributed magnetic field, and this domain extension was matched with the permeability variation. The result leads to the application of this phenomenon to a tunable inductor, electromagnetic shielding, or a sensor for detecting and memorizing the existence of a distributed magnetic field generated by a magnetic nanoparticle in the vicinity of the sensor.

  5. Permeability of Clustered Soft Magnetic Narrow Strips Controlled by a Surface Normal Magnetic Field Peer-reviewed

    Tomoo Nakai

    IEEE Transactions on Magnetics　2023/11

    DOI： 10.1109/TMAG.2023.3289139 　

  6. High-Frequency Permeability of Adjacent Narrow Strips Having an Inclined Magnetic Anisotropy Peer-reviewed

    Tomoo Nakai

    SPIN　13　(02)　2023/03/03

    Publisher: World Scientific Pub Co Pte Ltd

    DOI： 10.1142/s2010324723400039 　

    ISSN： 2010-3247

    eISSN： 2010-3255

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    This study deals with a phenomenon of magnetic domain transition of adjacent narrow thin film strips with inclined uniaxial magnetic anisotropy. Our previous research shows that individual element with 70° inclined easy magnetization axis has a typical characteristic of the domain transition, and the transition can be controlled by the normal magnetic field. We also applied this phenomenon and controlling method to the two-dimensional configuration of line arrangement adjacent to many-body elements, in which mutual magnetic interaction exists. The result shows that the hidden inclined Landau–Lifshitz domain appears by applying a distributed normal field the same as an individual single element. This paper reports a comprehensive magnetic property, such as magnetic domains, magnetic hysteresis-loop (MH-loop), and high-frequency permeability of the adjacent many-body elements, in some fabrication conditions surrounding the exact condition where the hidden inclined Landau–Lifshitz domain appears. The result shows an estimation of a switched device of high-frequency permeability caused by the switched magnetic domain using the hidden domain and the control of distributed normal field. This phenomenon would be expected to apply functional devices, such as a switched inductor or a switched electromagnetic shielding, or a magnetic sensor.

  7. Study on Detection of a Small Magnetic Particle Using Thin Film Magneto-Impedance Sensor with Subjecting to Strong Normal Field Peer-reviewed

    Tomoo Nakai

    Micromachines　13　(8)　1199　2022/07/28

    Publisher: MDPI AG

    DOI： 10.3390/mi13081199 　

    eISSN： 2072-666X

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    This paper deals with the detection of small magnetization using a thin film magneto-impedance sensor with subjecting to strong normal field. The sensor was made by soft magnetic amorphous thin-film with uniaxial magnetic anisotropy in the width direction of the element. It was reported that the sensor has very high sensitivity, such as pico-tesla order, when it is driven by hundreds of MHz. In this paper, a sensitive measurement method aiming for detection of a small particle or a cluster of nano-particles, having low-remanence, is proposed. The point is the application of strong normal field in the measurement area including sensor element and particle. The normal strong field is applied in the normal direction of the sensor plane in the value almost hundreds of mT. Instead of such strong normal field, the sensor keeps high sensitivity, because of the demagnetizing force in the thickness direction. A theoretical estimation for clarifying an efficiency of the method, experimental results of sensor property and sensitivity with subjecting to the normal field, and also a confirmation of detection of a small particle using the proposed method is reported. As a special mention, detection fundamentals when a applied surface normal field has a distribution and also a particle would run through in the vicinity of sensor is discussed.

  8. A Uniform Magnetic Field Generator Combined with a Thin-Film Magneto-Impedance Sensor Capable of Human Body Scans Peer-reviewed

    Tomoo Nakai

    Sensors　22　(9)　3120　2022/04/19

    Publisher: MDPI AG

    DOI： 10.3390/s22093120 　

    eISSN： 1424-8220

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    A detection system for magnetic inclusions of large bulk, such as that of a whole human body, is proposed in this paper. The system consists of both a uniform magnetic field generating apparatus capable of the insertion of a whole human body and also of a high-sensitivity magnetic sensor array installed in the strong magnetic field. The system can detect the magnetic inclusion simultaneously through its magnetization, which is advantageous for detecting low-remanence magnetic materials, such as a cluster of nanoparticles. The thin-film magneto-impedance sensor was reported to be capable of tolerating strong magnetic fields of more than 3000 Gauss (0.3 T) in the substrate’s normal direction and can retain its sensitivity even in strong fields. Through a combination of both uniformity of strength and the placement of its directionally aligned, static magnetic field in a particular measurement area and its array of single-dimensional thin-film magneto-impedance sensors, it was reported that it can estimate a magnetic sample’s 3D position by using a simple equation. The aim of the system developed in this study is to nondestructively detect a cluster of magnetic nanoparticles in a human body and also to detect the position and the concentration of the clustered magnetic particles. In this paper, a prototype system consisting of a magnetic field generator with an area of W500 mm × L400 mm × H210 mm and a uniform magnetic field of 370 Gauss (37 mT) is reported. It also reported that the thin-film magneto-impedance sensor installed in the system verified the detection of 2 mm × 1 mm small ellipsoidal magnetic chips at a distance of 27 mm from the sensor element.

  9. Estimation of Position and Size of a Contaminant in Aluminum Casting Using a Thin-Film Magnetic Sensor Peer-reviewed

    Tomoo Nakai

    Micromachines　13　(1)　127　2022/01/14

    Publisher: MDPI AG

    DOI： 10.3390/mi13010127 　

    eISSN： 2072-666X

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    Advanced manufacturing processes require an in-line full inspection system. A nondestructive inspection system able to detect a contaminant such as tool chipping was utilized for the purpose of detecting a defective product as well as damaged machine tools used to fabricate the product. In a previous study, a system able to detect magnetic tool steel chipping in conductive material such as aluminum was developed and tested. In this study, a method of position and size estimation for magnetic chipping was investigated and is described. An experimental confirmation of the proposed method was also carried out using an actual prototype system.

  10. Nondestructive Detection of Magnetic Contaminant in Aluminum Casting Using Thin Film Magnetic Sensor Peer-reviewed

    Tomoo Nakai

    Sensors　21　(12)　4063　2021/06/12

    Publisher: MDPI AG

    DOI： 10.3390/s21124063 　

    eISSN： 1424-8220

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    The thin film magneto-impedance sensor is useful for detecting a magnetic material nondestructively. The sensor made by single layer uniaxial amorphous thin film has a tolerance against surface normal magnetic field because of its demagnetizing force in the thickness direction. Our previous study proposed the sensitive driving circuit using 400 MHz high frequency current running through the sensor to detect the logarithmic amplifier. We also confirmed the sensitivity of the sensor within 0.3 T static normal magnetic field, which resulted in detection of 5 × 10−8 T of 5 Hz signal. This paper proposes a nondestructive inspection system for how detecting a contaminant of small tool steel chipping in aluminum casting specimen would be carried out. Three channel array sensors installed in the 30 mT static field detecting area were fabricated and experimentally showed a detection of low remanence magnetic contaminant in a bulk aluminum casing specimen.

  11. Property and Magnetic Domain of Thin Film MI Sensor with Subjecting to Normal Magnetic Field Peer-reviewed

    Tomoo Nakai

    IEEJ Transactions on Sensors and Micromachines　140　(12)　343-348　2020/12/01

    Publisher: Institute of Electrical Engineers of Japan (IEE Japan)

    DOI： 10.1541/ieejsmas.140.343 　

    ISSN： 1341-8939

    eISSN： 1347-5525

  12. Sensitivity of Thin Film Magnetoimpedance Sensor in 0.3 T Surface Normal Magnetic Field Peer-reviewed

    Tomoo Nakai

    IEEJ Transactions on Electrical and Electronic Engineering　15　(8)　1230-1235　2020/06/29

    Publisher: Wiley

    DOI： 10.1002/tee.23186 　

    ISSN： 1931-4973

    eISSN： 1931-4981

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    Detection of foreign matters and nanoparticles included in industrial and chemical products is an important application target for a sensor system. There is a need to detect a small piece of steel tool chipping or breakage included in the products nondestructively. A recent improvement of the manufacturing system strongly required an inspection of all items in every production process to realize the smart manufacturing system. A thin‐film magnetic field sensor is an impressive candidate for this target as it has an extremely high sensitivity, especially because it is driven by alternating current around hundreds of MHz, and it is also tolerant to a surface normal magnetic field due to its demagnetizing force in the thickness direction. In this study, the sensitivity of a sensor system that was created by applying a 0.3 T normal field to the detection area included in a sensor element and also by using a 400‐MHz high‐frequency driven thin‐film magnetoimpedance sensor was evaluated. An observation of the magnetic domain was also carried out at the same time as the sensitivity evaluation. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

  13. Magnetic Domain Transition of Adjacent Narrow Thin Film Strips with Inclined Uniaxial Magnetic Anisotropy Peer-reviewed

    Tomoo Nakai

    Micromachines　11　(3)　279　2020/03/08

    Publisher: MDPI AG

    DOI： 10.3390/mi11030279 　

    eISSN： 2072-666X

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    This study deals a phenomenon of magnetic domain transition for the stepped magneto-impedance element. Our previous research shows that an element with 70° inclined easy axis has a typical characteristic of the domain transition, and the transition can be controlled by the normal magnetic field. In this paper, we apply this phenomenon and controlling method to the line arrangement adjacent to many body elements, in which mutual magnetic interaction exists. The result shows that the hidden inclined Landau–Lifshitz domain appears by applying a distributed normal field the same as an individual element.

  14. Magneto-Impedance Sensor Driven by 400 MHz Logarithmic Amplifier Peer-reviewed

    Tomoo Nakai

    Micromachines　10　(6)　355　2019/05/29

    Publisher: MDPI AG

    DOI： 10.3390/mi10060355 　

    eISSN： 2072-666X

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    A thin-film magnetic field sensor is useful for detecting foreign matters and nanoparticles included in industrial and medical products. It can detect a small piece of tool steel chipping or breakage inside the products nondestructively. An inspection of all items in the manufacturing process is desirable for the smart manufacturing system. This report provides an impressive candidate for realizing this target. A thin-film magneto-impedance sensor has an extremely high sensitivity, especially, it is driven by alternatiing current (AC) around 500 MHz. For driving the sensor in such high frequency, a special circuit is needed for detecting an impedance variation of the sensor. In this paper, a logarithmic amplifier for detecting a signal level of 400 MHz output of the sensor is proposed. The logarithmic amplifier is almost 5 mm × 5 mm size small IC-chip which is widely used in wireless devices such as cell phones for detecting high-frequency signal level. The merit of the amplifier is that it can translate hundreds of MHz signal to a direct current (DC) voltage signal which is proportional to the radio frequency (RF)signal by only one IC-chip, so that the combination of a chip Voltage Controlled Oscillator (VCO), a magneto-impedance (MI) sensor and the logarithmic amplifier can compose a simple sensor driving circuit.

  15. Magnetic domain transition controlled by distributed normal magnetic field for stepped magneto-impedance sensor Peer-reviewed

    Tomoo Nakai

    International Journal of Applied Electromagnetics and Mechanics　59　(1)　105-114　2019/03/21

    Publisher: SAGE Publications

    DOI： 10.3233/jae-171005 　

    ISSN： 1383-5416

    eISSN： 1875-8800

  16. Magnetic Domain of Stepped Magneto-Impedance Sensor Controlled by a Normal Magnetic Field Peer-reviewed

    Tomoo Nakai

    IEEJ Transactions on Sensors and Micromachines　138　(1)　23-29　2018/01

    Publisher: Institute of Electrical Engineers of Japan (IEE Japan)

    DOI： 10.1541/ieejsmas.138.23 　

    ISSN： 1341-8939

    eISSN： 1347-5525

  17. Effects of DC Bias Current on Behavior and Sensitivity of Thin-Film Magnetoimpedance Element Peer-reviewed

    H. Kikuchi, C. Sumida, T. Nakai, S. Hashi, K. Ishiyama

    IEEE TRANSACTIONS ON MAGNETICS　53　(11)　2017/11

    DOI： 10.1109/TMAG.2017.2703886 　

    ISSN： 0018-9464

    eISSN： 1941-0069

  18. Partially Implicit Method for Fast Magnetization Analysis Using Assembled Domain Structure Model Peer-reviewed

    Shogo Tejima, Shumpei Ito, Takeshi Mifune, Tetsuji Matsuo, Tomoo Nakai

    IEEE Transactions on Magnetics　53　(6)　1-4　2017/06

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tmag.2017.2661338 　

    ISSN： 0018-9464

    eISSN： 1941-0069

  19. Magnetization analysis of stepped giant magneto impedance sensor using assembled domain structure model Peer-reviewed

    Shogo Tejima, Shumpei Ito, Takeshi Mifune, Tetsuji Matsuo, Tomoo Nakai

    International Journal of Applied Electromagnetics and Mechanics　52　(1-2)　541-546　2016/12/29

    Publisher: SAGE Publications

    DOI： 10.3233/jae-162049 　

    ISSN： 1383-5416

    eISSN： 1875-8800

  20. Improvement of Stepped Magnetoimpedance Properties by Controlling the Demagnetizing Effect Peer-reviewed

    H. Kikuchi, S. Kamata, S. Oe, T. Nakai, S. Hashi, K. Ishiyama

    IEEE Transactions on Magnetics　51　(11)　1-4　2015/11

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tmag.2015.2441748 　

    ISSN： 0018-9464

    eISSN： 1941-0069

  21. Influence of demagnetizing field on thin-film GMI magnetic sensor elements with uniaxial magnetic anisotropy Peer-reviewed

    Hiroaki Kikuchi, Shingo Kamata, Tomoo Nakai, Shuichiro Hashi, Kazushi Ishiyama

    Sensors and Actuators A: Physical　230　142-149　2015/07

    Publisher: Elsevier BV

    DOI： 10.1016/j.sna.2015.04.027 　

    ISSN： 0924-4247

  22. Enhancement of Sensitivity on Miniaturized Thin-film Magnetoimpedance with Ellipsoidal Element

    Hiroaki Kikuchi, Suguru Oe, Hiroaki Uetake, Shin Yabukami, Tomoo Nakai, Shuichiro Hashi, Kazushi Ishiyama

    20TH INTERNATIONAL CONFERENCE ON MAGNETISM, ICM 2015　75　1271-1278　2015

    DOI： 10.1016/j.phpro.2015.12.141 　

    ISSN： 1875-3892

  23. Investigation of Driving Power Dependence on Magnetoimpedance Properties of Thin-Film Elements With Uniaxial Anisotropy Peer-reviewed

    Hiroaki Kikuchi, Shingo Kamata, Yosuke Takahashi, Tomoo Nakai, Shuichiro Hashi, Kazushi Ishiyama

    IEEE Transactions on Magnetics　51　(1)　1-4　2015/01

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tmag.2014.2358221 　

    ISSN： 0018-9464

    eISSN： 1941-0069

  24. Effects of easy axis direction on the magnetoimpedance properties of thin films with uniaxial anisotropy Peer-reviewed

    H. Kikuchi, Y. Takahashi, K. Takahashi, T. Nakai, S. Hashi, K. Ishiyama

    JOURNAL OF APPLIED PHYSICS　115　(17)　17A303　2014/05

    DOI： 10.1063/1.4859095 　

    ISSN： 0021-8979

    eISSN： 1089-7550

  25. Impedance Variation with Subjecting to Normal Field for the Stepped Giant Magnetoimpedance Element Peer-reviewed

    Tomoo Nakai, Kazushi Ishiyama

    IEEE Transactions on Magnetics　50　(1)　1-4　2014/01

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tmag.2013.2276741 　

    ISSN： 0018-9464

    eISSN： 1941-0069

  26. Development of Magnetic Crack Detection System Using Thin Film Magnetic Field Sensor Peer-reviewed

    T. Ozawa, H. Yamada, K. Sato, K. Kojima, S. Yabukami, N. Kobayashi, T. Nakai, K.I. Arai

    Journal of the Magnetics Society of Japan　37　(1)　1-7　2013/01

    Publisher: The Magnetics Society of Japan

    DOI： 10.3379/msjmag.1211r001 　

    ISSN： 1882-2924

    eISSN： 1882-2932

  27. 高周波キャリア型薄膜磁界センサを利用した磁気探傷の試み

    小澤 哲也, 谷地館 藍, 山田 洋, 佐藤 弘二, 小島 健, 薮上 信, 小林 伸聖, 中居 倫夫, 荒井 賢一

    電気関係学会東北支部連合大会講演論文集　2011　256-256　2011

    Publisher: 電気関係学会東北支部連合大会実行委員会

    DOI： 10.11528/tsjc.2011.0_256 　

  28. Scanning System Using Transmission Line Type Thin Film Sensor Peer-reviewed

    K. Sato, K. Kojima, S. Yabukami, T. Ozawa, N. Kobayashi, T. Nakai, K.I. Arai

    Journal of the Magnetics Society of Japan　35　(2)　76-81　2011

    Publisher: The Magnetics Society of Japan

    DOI： 10.3379/msjmag.1102r007 　

    ISSN： 1882-2924

    eISSN： 1882-2932

  29. Study of dynamic process of domain change in the stepped giant magnetoimpedance element Peer-reviewed

    T Nakai, K Takada, K Ishiyama

    Journal of Physics: Conference Series　200　(4)　042019-042019　2010/01/01

    Publisher: IOP Publishing

    DOI： 10.1088/1742-6596/200/4/042019 　

    eISSN： 1742-6596

  30. Existence of Three Stable States of Magnetic Domain for the Stepped Giant Magnetoimpedance Element and Proposal for Sensor With Memory Function Peer-reviewed

    T. Nakai, K. Takada, K. Ishiyama

    IEEE Transactions on Magnetics　45　(10)　3499-3502　2009/10

    Publisher: Institute of Electrical and Electronics Engineers (IEEE)

    DOI： 10.1109/tmag.2009.2022416 　

    ISSN： 0018-9464

  31. Study of Large Barkhauzen Sensor with Application of Step-like Giant Magnetoimpedance Element Peer-reviewed

    T. Nakai, K. Takada, K. Ishiyama

    Journal of the Magnetics Society of Japan　33　(3)　287-292　2009

    Publisher: The Magnetics Society of Japan

    DOI： 10.3379/msjmag.0903rf8030 　

    ISSN： 1882-2924

    eISSN： 1882-2932

  32. Study of hysteresis for steplike giant magnetoimpedance sensor based on magnetic energy Peer-reviewed

    T. Nakai, K. Ishiyama, J. Yamasaki

    Journal of Magnetism and Magnetic Materials　320　(20)　e958-e962　2008/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.jmmm.2008.04.086 　

    ISSN： 0304-8853

  33. Variation of the Magnetic Field in which the Impedance Step Occurs as a Function of the Applied Magnetic Field for a Step-Like GMI Element Peer-reviewed

    T. Nakai, K. Takada, H. Komatsu, K. Ishiyama

    Journal of the Magnetics Society of Japan　32　(3)　366-370　2008

    Publisher: The Magnetics Society of Japan

    DOI： 10.3379/msjmag.32.366 　

    ISSN： 1882-2924

    eISSN： 1882-2932

  34. Analysis of steplike change of impedance for thin-film giant magnetoimpedance element with inclined stripe magnetic domain based on magnetic energy Peer-reviewed

    T. Nakai, K. Ishiyama, J. Yamasaki

    Journal of Applied Physics　101　(9)　2007/05/01

    Publisher: AIP Publishing

    DOI： 10.1063/1.2711073 　

    ISSN： 0021-8979

    eISSN： 1089-7550

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    The phenomenon of steplike impedance change for thin-film giant magnetoimpedance (GMI) element was reported. The steplike change happens simultaneously with the appearance or the disappearance of stripe magnetic domain. This phenomenon is obtained for amorphous Co85Nb12Zr3 soft magnetic thin film in a rectangle shape with an in-plane uniaxial easy axis in the direction nearly 60° against the short-side axis of the element. The steplike change of impedance appears in a certain magnitude of external magnetic field. A high-sensitive magnetic field sensor can be realized by applying this phenomenon. In this study, a mechanism of the appearance or the disappearance of inclined stripe magnetic domain is discussed based on an analysis of magnetic domain energy, for the purpose of applying to a high-sensitivity magnetic field sensor. We assume these extremely different magnetic domains as (I) stripe domain with closure domain and (II) single domain, based on experimentally observed domain structures. The result of analysis shows that the magnetic energy of these two phases intersects each other in a certain external magnetic field, which means that the basis of steplike GMI of thin-film element is revealed as a structural change of magnetic domain based on magnetic energy.

  35. 不連続的インピーダンス変化特性を有した薄膜GMIセンサと微分回路を組合せた磁界検出方法に関する検討 Peer-reviewed

    中居 倫夫, 高田 健一, 阿部 宏之, 星 則光, 鈴木 秀夫, 石山 和志, 荒井 賢一

    2007

  36. Impedance-step phenomenon of thin-film GMI element with inclined magnetic stripe domain Peer-reviewed

    T. Nakai, H. Abe, K. I. Arai

    The Physics of Metals and Metallography　101　(S1)　S41-S44　2006/07

    Publisher: Pleiades Publishing Ltd

    DOI： 10.1134/s0031918x06130138 　

    ISSN： 0031-918X

    eISSN： 1555-6190

  37. 反射信号を用いた高周波キャリア型磁界センサによる微小交流磁界計測に関する研究 Peer-reviewed

    中居 倫夫, 仙道 雅彦, 薮上 信, 石山 和志, 荒井 賢一

    2006

  38. 端部磁性体を配置した高周波キャリア型磁界センサの感度向上に関する研究 Peer-reviewed

    仙道 雅彦, 中居 倫夫, 橘 奈緒子, 星 則光, 鈴木 秀夫, 堀越 直, 薮上 信, 石山 和志, 荒井 賢一

    2006

  39. Impedance property of thin film GMI sensor with controlled inclined angle of stripe magnetic domain Peer-reviewed

    T. Nakai, H. Abe, S. Yabukami, K.I. Arai

    Journal of Magnetism and Magnetic Materials　290-291　1355-1358　2005/04

    Publisher: Elsevier BV

    DOI： 10.1016/j.jmmm.2004.11.436 　

    ISSN： 0304-8853

  40. 高周波キャリア型磁界センサにおける不連続的インピーダンス変化特性の素子長さ依存性 Peer-reviewed

    中居 倫夫, 阿部 宏之, 荒井 賢一

    2005

  41. 不連続的特性を有した高周波キャリア型磁界センサにおけるインピーダンス特性の温度変化 Peer-reviewed

    中居 倫夫, 阿部 宏之, 荒井 賢一

    2005

  42. 傾斜磁区構造を有する高周波キャリア型磁界センサにおける検出方向外部磁場による磁区構造変化とインピーダンス変化 Peer-reviewed

    中居 倫夫, 薮上 信, 荒井 賢一

    2004

  43. コプレーナ配置した薄膜磁石バイアス構造を有する高周波キャリア型磁界センサ Peer-reviewed

    中居 倫夫, 山口 正洋, 石山 和志, 荒井 賢一

    2004

  44. マイクロ波測定用プローブを用いたコプレーナ型高周波キャリア型磁界センサの特性評価 Peer-reviewed

    中居 倫夫, 阿部 宏之, 山口 正洋, 薮上 信, 菊池 弘昭, 荒井 賢一

    2003

  45. 高周波キャリア型磁界センサにおける傾斜磁区制御方法とインピーダンス特性 Peer-reviewed

    中居 倫夫, 阿部 宏之, 薮上 信, 山口 正洋, 荒井 賢一

    2003

  46. Remarkable improvement of sensitivity for high-frequency carrier-type magnetic field sensor with ferromagnetic resonance Peer-reviewed

    T. Nakai, M. Yamaguchi, H. Kikuchi, H. Iizuka, K.I. Arai

    Journal of Magnetism and Magnetic Materials　242-245　1142-1145　2002/04

    Publisher: Elsevier BV

    DOI： 10.1016/s0304-8853(01)01305-1 　

    ISSN： 0304-8853

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Presentations 16

  1. Analysis of Magnetic Domain Transition for Magnetostrictive Co-Nb-Zr Thin Film Strips with Inclined Uniaxial Easy-Axis

    Tomoo Nakai

    IEEE Intermag 2026　2026/04/13

  2. Magnetic Domain Transition of Clustered Soft Magnetic Narrow Strips Caused by a Magnetic Small Particle

    Tomoo Nakai

    IEEE Sensors 2023　2023/10

  3. Permeability of Clustered Soft Magnetic Narrow Strips Controlled by a Surface Normal Magnetic Field

    Tomoo Nakai

    IEEE Intermag 2023　2023/06

  4. Proposal of Electrical Energy Harvester Using Ring-Shape Magnets and FeCo Magnetic Core

    Tomoo Nakai

    15th International Conference on Motion and Vibration　2020/09

  5. Magnetic Domain Transition Controlled by Distributed Normal Magnetic Field for Stepped Magneto-Impedance Sensor

    Tomoo Nakai

    ISEM 2017 (18th International Symposium on Applied Electromagnetics and Mechanics)　2017/09

  6. Magnetic Domain Observation of Stepped Giant Magneto-Impedance Sensor with Subjecting to Normal Magnetic Field Invited

    Tomoo Nakai

    IEEE Sensors 2015　2015/11

  7. Thin-Film Giant Magneto-Impedance Sensor with Applying Normal Magnetic Field Invited

    Tomoo Nakai

    2015 Energy Materials Nanotechnology (EMN) Istanbul Meeting　2015/07

  8. Interaction Between HFC-Type Thin-Film Magnetic Sensor and Small Particle with Subjecting to Strong Normal Field

    Tomoo Nakai, Kazushi Ishiyama

    59th annual conference on magnetism and magnetic materials (MMM2014)　2014/11

  9. Reconstruction of Magnetic Domain for the Stepped Giant Magneto-Impedance Element by Applying Normal Field

    Tomoo Nakai, Kazushi Ishiyama

    The 3rd International Symposium on Advanced Magnetic Materials and Applications (ISAMMA2013)　2013/07

  10. Study of Dynamics of Domain Change in the Stepped Giant Magneto-Impedance Element

    Tomoo Nakai, Kenichi Takada, Kazushi Ishiyama

    International Conference on Magnetism (ICM2009)　2009/07

  11. Existence of Three Stable States of Magnetic Domain for the Stepped Giant Magneto-Impedance Element and a Proposal for a Sensor with Memory Function

    Tomoo Nakai, Kenichi Takada, Kazushi Ishiyama

    IEEE Intermag 2009　2009/05

  12. Property of a Step Point Occurrence for the Step-like Giant Magneto-Impedance Phenomenon and Stability of the Step Point Magnetic Field

    Tomoo Nakai, Kazushi Ishiyama, Jiro Yamasaki

    18th Soft Magnetic Materials Conference (SMM 18)　2007/09

  13. Mechanism of Step-like Change of Impedance for Thin-film GMI Element with Inclined Stripe Magnetic Domain

    Tomoo Nakai, Kazushi Ishiyama, Jiro Yamasaki

    10th IEEE MMM/Intermag Conference　2007/01

  14. Property Control Method of a Thin-Film GMI Sensor Based on Controlling an inclined Angle of Stripe Magnetic Domain

    Tomoo Nakai, Hiroyuki Abe, Shin Yabukami, Ken-Ichi Arai

    Joint European Magnetic Symposia (JEMS’04)　2004/09

  15. Impedance Step Phenomenon of Thin-Film GMI Element with Inclined Magnetic Stripe Domain

    Tomoo Nakai, Hiroyuki Abe, Ken-Ichi Arai

    Euro-Asian Symposium “Trends in Magnetism” (EASTMAG-2004)　2004/08

  16. Remarkable Improvement of Sensitivity for High-Frequency Carrier-Type Magnetic Field Sensor with Ferromagnetic Resonance

    Tomoo Nakai, Masahiro Yamaguchi, Hiroaki Kikuchi, Hisakazu Iizuka, Ken-Ichi Arai

    Joint European Magnetic Symposia (JEMS’01)　2001/08

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Research Projects 2

  1. 磁気センサ Competitive

  2. Magnetic sensor Competitive