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141 results on '"Sonehara, Makoto"'

16. Crossed Anisotropy Multilayered Nanogranular Films Combining High Permeability, Ferromagnetic Resonance Frequency, and Resistivity

Author

Naoe, Masayuki, Sonehara, Makoto, Miyaji, Kousuke, Sato, Toshiro, Endo, Yasushi, Muroga, Sho, Kobayashi, Nobukiyo, and Arai, Ken-Ichi

Abstract

In-plane isotropic crossed anisotropy multilayer for high-frequency magnetics was fabricated using in-plane uniaxial anisotropic nanogranular film owing to its high permeability, ferromagnetic resonance (FMR) frequency, and electrical dc resistivity. The multilayer exhibited in-plane isotropy and enabled us to combine permeability of approximately 100, FMR frequency of approximately 3 GHz, and resistivity of approximately $5 ~\mu \Omega \cdot \text {m}$ . Moreover, a low damping factor of 0.0148 was obtained; hence the multilayer is available for a low loss of up to 1 GHz. Meanwhile, the underlayer and cap layer were necessary for improving the isotropy of the multilayer. The results can be attributed to the interfacial stress.

Published
2023
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17. Reducing heat generation in a boost inductor using a magnetic tape.

Author

Shimura, Kazuhiro, Kanaya, Takanori, Hoshina, Syuichi, Kobayashi, Shigeki, Sato, Mitsuhide, Sonehara, Makoto, Sato, Toshiro, and Mizuno, Tsutomu

Subjects
MAGNETIC tapes, MAGNETIC flux, HEAT losses, DC-to-DC converters, TEMPERATURE effect
Abstract

Increasing the switching frequency of direct current–direct current converters is effective in reducing the size of magnetic components used in converters. However, as the switching frequency increases, the loss and heat generated by the magnetic components increase. Therefore, in this study, a magnetic tape that bypasses the magnetic flux in the windings of magnetic components is proposed to reduce the loss and heat generation of these components. The effect of suppressing the temperature rise of magnetic components with a magnetic tape during the converter drive was investigated. The temperature rise of a 1-MHz 100-V/200-V 800-W boost inductor was reduced by 16.8 K by applying the magnetic tape. Additionally, applying the magnetic tape to the inductor reduced the heat generation. [ABSTRACT FROM AUTHOR]

Published
2023
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25. Preparation and characterization of nanofiber nonwoven textile for electromagnetic wave shielding

Author

Sonehara, Makoto, Sato, Toshiro, Takasaki, Midori, Konishi, Hajime, Yamasawa, Kiyohito, and Miura, Yoshimasa

Subjects
Electric waves -- Analysis, Electromagnetic radiation -- Analysis, Electromagnetic waves -- Analysis, Electron spin -- Analysis, Nonwoven fabrics -- Production processes, Nonwoven fabrics -- Properties, Business, Electronics, Electronics and electrical industries
Abstract

A nanofiber nonwoven textile with metallic magnetic material coating was fabricated, and the effect of electromagnetic wave shielding was evaluated. The nanofiber nonwoven textile with an average diameter of about 500 nm was spun by electrospinning. The metallic magnetic material was coated by sputtering on the textile surface. EMI shielding effect of the textile with metallic magnetic material coating was about 90% in the GHz band. Because the textile has thin, light, flexible, and breathable characteristics, it will be versatile for various electromagnetic wave shielding applications. Index Terms--Electromagnetic wave shielding, electrospinning, metallic magnetic material, nanofiber nonwoven textile, sputtering.

Published
2008

38. Relation between microwave complex permeability and ferromagnetic Fe-Si layer thickness in Mn-Ir/Fe-Si exchange-coupled film

Author

Sonehara, Makoto, Sugiyama, Takatoshi, Ishikawa, Takuya, Inagaki, Kei, Sato, Toshiro, Yamasawa, Kiyohito, and Miura, Yoshimasa

Subjects
Ferromagnetism -- Research, Electromagnetism -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Mn-Ir/Fe-Si exchange-coupled films with an Ru underlayer for high frequency applications were fabricated, and their microwave permeability was evaluated. Both exchange bias field and ferromagnetic resonance frequency increased with decreasing Fe-Si thickness. For example, Mn-Ir (10 nm)/Fe-Si (10 nm)/Ru (1 nm) exchange-coupled film deposited on Si[O.sub.2] had a static relative permeability of about 180 and a ferromagnetic resonance (FMR) frequency of about 4.3 GHz. The microwave properties such as permeability and FMR frequency can be controlled by changing Fe-Si thickness. Index Terms--Exchange-coupling, Fe-Si, ferromagnetic resonance frequency, high-frequency micromagnetic devices, Mn-Ir.

Published
2006

44. Preparation and characterization of Mn-Ir/Fe-Si exchange-coupled multilayer film with Ru underlayer for high-frequency applications

Author

Sonehara, Makoto, Sugiyama, Takasugi, Sato, Toshiro, Yamasawa, Kiyohito, and Miura, Yoshimasa

Subjects
Anisotropy -- Magnetic properties, Manganese -- Magnetic properties, Business, Electronics, Electronics and electrical industries
Abstract

Fe-Si magnetic film and Mn-Ir/Fe-Si exchange-coupled film with an Ru underlayer were fabricated and evaluated. Both coercivity and anisotropy dispersion were reduced due to the Ru underlayer effect on the magnetic properties of Fe-Si magnetic film and Mn-Ir/Fe-Si exchange-coupled film. Even in the Mn-Ir/Fe-Si exchange-coupled multilayer film with an Ru underlayer, the coercivity of the upper Fe-Si layer was reduced. Index Terms--Exchange coupling, Fe-Si, high-frequency micromagnetic device, Mn-Ir, Ru underlayer, small anisotropy dispersion.

Published
2005

50. Fundamental Study of Optical Probe Current Sensor using Kerr Effect of Single Magnetic Domain Film

Author

Sonehara, Makoto, Otani, Naoki, Goto, Takanori, Kikuchi, Yusuke, Sato, Toshiro, Yamasawa, Kiyohito, Miura, Yoshimasa, and Asanuma, Kazushi

Abstract

IEEE SENSORS 2009 Conference, 25-28 October 2009. Christchurch Convention Centre in New Zealand, This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder., An optical probe current sensor using a Kerr effect ofan Fe-Si/Mn-Ir exchange-coupled film has been investigated. The optical sensing technique has the advantage of no induced noise from the external electromagnetic interference. In addition, since the proposed method using the Kerr effect of single domain exchange-coupled magnetic thin film utilizes only magnetization rotation, the Barkhausen noise due to a domain wall pinning can be excluded. A fabricated optical probe current sensor consisting of He-Ne laser,e-Si/Mn-Ir exchange-coupled film, beam splitter, pin-PD and differential amplifier, exhibited a current sensing bandwidth of 10 kHz and a sensitivity of 2.26 V/A. By using the fabricated optical probe current sensor, the current sensing for PWM inverter motor has been demonstrated., Article, IEEE SENSORS 2009 Conference : 1232-1237 (2009)

Published
2009

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