研究者詳細 - 吉村　哲

An α"-Fe16N2 has very high magnetic crystalline anisotropy energy even if magnetic anisotropy field is not so large because of its very high saturation magnetization. Therefore, magnetization switching field of this material is smaller than that of L10-FePt which has very high magnetic crystalline anisotropy energy due to having very high magnetic anisotropy field. As the results, α"-Fe16N2 seems one of the suitable materials for next-generation high density magnetic recording media without energy assisted recording system. In this study, for fabrication of α"-Fe16N2 thin fi lms, we newly attempted a pulsed DC（P-DC） reactive sputtering method, which is expected to provide high quality in the formation of oxide/nitride thin films with complex crystal structures. Since there have been no attempts to fabricate this thin fi lms with this method before, we investigated the influence of film properties （composition） on deposition parameters such as pulse frequency, deposition power, and target-substrate （T-S） distance, and fi nally optimized the deposition conditions to obtain the nitrogen concentration of Fe:N ＝ 16:2 in the film. As a result, with decreasing pulse frequency, with increasing deposition power, and with decreasing T-S distance, nitrogen concentration in the thin fi lm decreased, and it was clear that the optimized deposition conditions to obtain the nitrogen concentration of Fe:N ＝ 16:2 in the thin fi lm were pulse frequency: 25 kHz, deposition power: 200 W, and T-S distance: 100 mm, respectively. Using these deposition conditions, we investigated the deposition temperature and VHF plasma irradiation power to promote the α" phase formation and crystallization in the fabrication of Fe-N thin films on MgO（100） single crystalline substrates. As a result, it was found that α" phase formation and crystallization were most enhanced at a deposition temperature of 200 ℃ and a VHF plasma irradiation power of 3 W （Vdc: -18 to -16 V）. The usefulness of P-DC power source for fabrication of α"-Fe16N2 thin fi lms was confi rmed by comparing to Fe-N thin fi lms fabricated by using a DC power source. As a result, reactive P-DC sputtering method was found to have a positive impact on α" phase formation and crystallization.

DOI CiNii Research

Analysis of substitution of bismuth cations in CoFe<inf>2</inf>O<inf>4</inf> nanoparticles and their influence on frequency and temperature-dependent dielectric and magnetodielectric properties

Biswajita Dash, Sunirmal Saha, Satoru Yoshimura, Soumyaranjan Ratha, and Jashashree Ray

Journal of Materials Science: Materials in Electronics ( Journal of Materials Science: Materials in Electronics ) 34 ( 36 ) 2023年12月 [査読有り]

研究論文（学術雑誌）国際共著

DOI

Magnetization reversal of [Co/Pd] perpendicular magnetic thin film dot on (Bi,La)(Fe,Co)O<inf>3</inf>multiferroic thin film by applying electric field

Satoru Yoshimura, Naoya Oshita, Genta Egawa, and Munusamy Kuppan

Nanotechnology ( Nanotechnology ) 34 ( 46 ) 465703 2023年08月 [査読有り] [招待有り]

研究論文（学術雑誌）国内共著

DOI

Synergistic Effect of Allium-like Ni9S8 & Cu7S4 Electrodeposited on Nickel Foam for Enhanced Water Splitting Activity

M. Mottakin, V. Selvanathan, Md. A. Islam, H. Almohamadi, N. H. Alharthi, S. Yoshimura, Md. Akhtaruzzaman

Chemistry - An Asian Journal ( Chemistry - An Asian Journal ) e202300532 2023年08月 [査読有り]

研究論文（学術雑誌）国際共著

DOI

Excellent magnetic properties in multiferroic BiFeO3 based thin films for magnetic devices application

Soumyaranjan Ratha, Munusamy Kuppan, Genta Egawa, Satoru Yoshimura

Nano-Structures & Nano-Objects ( Elsevier ) 35 101007 2023年07月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Facile electrodeposition of biphasic CuSx/CoSx nanostructures as bifunctional electrocatalysts for seawater splitting

M. Mottakin, Vidhya Selvanathan, Syaza Amira Razali, Md. Ariful Islam, Hamad Almohamadi, Nabeel H. Alharthi, Satoru Yoshimura, Md. Akhtaruzzaman

Electrochimica Acta ( Elsevier ) 463 142861 2023年07月 [査読有り]

研究論文（学術雑誌）国際共著

DOI

強磁性・強誘電(Bi,La)(Fe1-yMy)O3(M=Ni,Co)薄膜の磁気特性に及ぼすBサイトの置換元素および置換量の効果

鈴木悠太, 尾関拓海, 江川元太, 吉村哲

日本素材物性学会誌 ( 日本素材物性学会 ) 33 ( 1_2 ) 12 - 17 2023年04月 [査読有り]

研究論文（学術雑誌）国内共著

CiNii Research

Development of (Bi0.5L 0.5)(Fe0.7Co0.3)O3 (L=La, Nd, Sm, Gd, Dy) Tthin Films with Excellent Magnetic Properties for Magnetic Device Application

S. Ratha, D. Yamamoto, K. Takeda, M. Kuppan, G. Egawa, and S. Yoshimura

International Journal of the Society of Materials Engineering for Resources ( 日本素材物性学会 ) 25 ( 2 ) 174 - 178 2022年10月 [査読有り]

研究論文（学術雑誌）国内共著

(Bi0.5L0.5)(Fe0.7Co0.3)O3 (L = La, Nd, Sm, Gd, Dy) thin films with ferromagnetism and ferroelectricity were fabricated using pulsed DC sputtering technique to obtain high saturation magnetization, perpendicular magnetic anisotropy and large magnetic Kerr effect. These magnetic properties are very important for realization of high performance magnetic devices driven by electric field. All (Bi0.5L0.5)(Fe0.7Co0.3)O3 (L = La, Nd, Sm, Gd, Dy) thin films had relatively high saturation magnetization, perpendicular magnetic anisotropy and magnetic Kerr effect. Especially, (Bi0.5Nd0.5)(Fe0.7Co0.3)O3 thin film had a very high saturation magnetization of 140 emu/cm3 (1.40×105 A/m), a high perpendicular magnetic anisotropy of 2.6 at ratio of perpendicular coercivity against in-plane coercivity and (Bi0.5La0.5)(Fe0.7Co0.3)O3 thin film had a very high magnetic Kerr rotation angle of 0.72°. These magnetic properties were excellent compared with the case of (Bi0.5A0.5)FeO3 (A = Ca, Sr, Ba) thin films with the maximum value of 90 emu/cm3 (9.0×104 A/m) (for saturation magnetization), 0.8 (for ratio of Perpendicular coercivity against in-plane coercivity) and 0.03° (for magnetic Kerr rotation angle) which were fabricated previously. These magnetic properties are very important for realization of high performance magnetic devices driven by electric field.

DOI CiNii Research

Investigations on Spintronic RFeO₃ Crystals Grown by Optical Floating Zone Technique

P. Ramesh Babu, S. Kalainathan, and S. Yoshimura

International Journal of the Society of Materials Engineering for Resources ( 日本素材物性学会 ) 25 ( 2 ) 179 - 182 2022年10月 [査読有り] [招待有り]

研究論文（学術雑誌）国際共著

Magnetic crystals are physically important to know their intrinsic magnetic properties. Magnetic crystals are also technologically important and their creation has aided crystal growth significantly. Rareearth orthoferrites material (RFeO3) is one of the major components used in manufacturing sophisticated gadgets. This study focuses on the growth and physical properties of the optically generated RFeO3 (R=Y, Gd and Sm) single crystals. The floating zone method generates single crystals of 3-20 mm/h in the optical zone. The purity of the grown materials was confirmed from the Powder X-Ray Diffraction (PXRD) analysis. The addition of Gd to YFeO3 increases the lattice parameters of the material. Magnetic properties of the grown crystal were studied between 20-700 K. At high temperature, two anomalous effects were observed, one at (TSR=480 K) due to spin reorientation and the other is antiferromagnetic (AFM) to paramagnetic transitions at (TN= 670 K). Bloch parameter was also calculated. Microhardness value decreases nonlinearly. When the applied load is greater than 1.96 N, there is a transition from palmqvist to median crack due to the plastic deformation of the crystal. Controllable magnetic and mechanical characteristics will help to enhance performance of magnetic devices.

DOI CiNii Research

Development of BiFeO3-based multiferroic thin films with large saturation magnetization and perpendicular magnetic anisotropy -The effect of the Co substitution against Fe on magnetic properties-

T. Ozeki, D. Yamamoto, G. Egawa, and S. Yoshimura

Journal of the Magnetics Society of Japan ( 日本磁気学会 ) 46 ( 3 ) 64 - 69 2022年05月 [査読有り]

研究論文（学術雑誌）国内共著

High saturation magnetization and perpendicular magnetic anisotropy are required for ferromagnetic / ferroelectric thin films to apply magnetic recording such as magnetic writing elements of magnetic wire memory, which is a next-generation device with very high recording density. To realize the magnetic properties, substitution of Co against Fe in (Bi1-xBax)FeO3 and (Bi1-xLax)FeO3 thin films were investigated. In the (Bi,Ba)(Fe,Co)O3 thin films, both Ba and Co substitution up to several tens at% had contribution to increase the saturation magnetization. The high saturation magnetization was obtained in (Bi,Ba)(Fe,Co)O3 thin films with the total composition of Ba and Co of around 60 at%. Further increment of Ba and Co substitution decreased the saturation magnetization because the formation of the BiFeO3 phase is hindered by an excess amount of Ba and Co with larger ion radius than Bi and Fe. Co substitution up to 20 at% had contribution to increase the perpendicular magnetic anisotropy. In the (Bi,La)(Fe,Co)O3 thin films, the effect of La substitution was not large to increase the saturation magnetization and perpendicular magnetic anisotropy, however the effect of Co substitution up to 30 at% was large to increase the saturation magnetization and perpendicular magnetic anisotropy.

DOI CiNii Research

超常磁性Co基グラニュラー薄膜の磁気特性の成膜速度依存性と新規反応性パルスDCスパッタリング成膜法の有用性の検討

小林拓海, 中田尭人, 江川元太, 吉村哲

日本素材物性学会誌 ( 日本素材物性学会 ) 32 ( 1_2 ) 22 - 27 2022年03月 [査読有り]

研究論文（学術雑誌）国内共著

The superparamagnetic thin films with a granular structure show a characteristic magnetization curve. In this study, Co-Al2O3 granular thin films were fabricated by the sputtering method with normal DC source for Co deposition, RF source for Al2O3 deposition, and pulsed DC reactive sputtering were used for fabrication of non-magnetic matrix of oxide or nitride of Al or Si. As a result, Co-Al2O3 superparamagnetic thin films with high magnetization could be obtained with high deposition rate. Very high deposition rate was obtained for fabrication of oxide or nitride films of Al or Si using the pulsed DC reactive sputtering method. This deposition rate was 5 times larger than RF sputtering method. It is expected that a sputtering method with DC source for Co deposition and pulsed DC source for matrix deposition will be effective to realize very high magnetization in the superparamagnetic granular thin films.

DOI CiNii Research

(Bi,A)FeO3薄膜（A＝Ca,Sr,Ba（アルカリ土類金属））の結晶構造と磁気特性におよぼすレーザーアシスト加熱成膜・後アニールの効果

鈴木陸, 尾関拓海, 江川元太, 吉村哲

日本素材物性学会誌 ( 日本素材物性学会 ) 32 ( 1_2 ) 15 - 21 2022年03月 [査読有り]

研究論文（学術雑誌）国内共著

High saturation magnetization is required for BiFeO3-based multiferroic（ferromagnetic/ferroelectric）thin films to apply magnetic writing element of Racetrack Memory which is a nextgeneration magnetic recording device. A newly introduced laser-assisted heating system was used to form high quality（Bi, A）FeO3（A=Ca, Sr, Ba（alkaline earth metal））thin films. The maximum substrate temperature was increased from 695 to about 858℃ by using this laserassisted heating system combining with lamp heating system of sputtering equipment. In the case of（Bi, Ca）FeO3 and（Bi, Sr）FeO3 with the Ca or Sr substitution concentration of 50～ 60 at％ fabricated by using the laser-assisted heating system, the crystallinity was improved, but oxygen vacancy could not be suppressed. As the result, saturation magnetization was not large. In the case of（Bi, Ba）FeO3 with the Ba substitution concentration of 50～60 at％ fabricated by using the laser-assisted heating system, oxygen vacancy could be suppressed. As the result, highest saturation magnetization of around 100 emu/cm3 was obtained in（Bi, Ba）FeO3 thin films.

DOI CiNii Research

High-resolution alternating magnetic force microscopy using an amorphous FeB-based tip driven by an inverse magnetostrictive effect: imaging of the high-density magnetic recording media

M. V. Makarova, Y. Akaishi, Y. Suzuki, K. S. Rao, S. Yoshimura, H. Saito

Journal of Magnetism and Magnetic Materials ( Journal of Magnetism and Magnetic Materials ) 546 ( 10 ) 168755 2022年01月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Magnetic properties of (Bi1−xLax)(Fe,Co)O3 films fabricated by a pulsed DC reactive sputtering and demonstration of magnetization reversal by electric field

Munusamy Kuppan, Daichi Yamamoto, Genta Egawa, Sivaperuman Kalainathan, Satoru Yoshimura

Scientific Reports ( Scientific Reports ) 11 11118-1 - 11118-8 2021年05月 [査読有り]

研究論文（学術雑誌）国際共著

DOI

反応性パルスDCスパッタリング成膜におけるBiFeO3系強磁性・強誘電薄膜の高品位作製の指針

武田航太朗, 山本大地, 吉村哲

日本磁気学会論文特集号 ( 公益社団法人日本磁気学会 ) 4 ( 2 ) 116 - 120 2020年09月 [査読有り]

研究論文（学術雑誌）国内共著

BiFeO3 based thin films with ferromagnetism were fabricated by using a pulsed DC reactive sputtering method. Guidelines on sputtering targets for fabricating the films are discussed in regard to obtaining high-quality BiFeO3 based thin films. By using a target with a low oxide content (low molar ratio of oxide) and thus good conductivity, it is possible to suppress the charging and arc discharge on the surface of the target and enable high-energy sputtering. As a result, high-quality BiFeO3 based thin films with a high saturation magnetization were formed. By using a target with a high oxygen content (including oxides with a high oxidation valence), the generation of oxygen vacancies that degrade the ferroelectric properties is suppressed, and pinning sites that suppress domain wall movement are then also suppressed. As a result, high-quality BiFeO3 based thin films with good ferromagnetic properties could be formed.

DOI CiNii Research

Alternating Magnetic Force Microscopy: Effect of Si doping on the temporal performance degradation of amorphous FeCoB magnetic tips

Makarova, Y. Akaishi, T. Ikarashi, K. S. Rao, S. Yoshimura, and H. Saito

Journal of Magnetism and Magnetic Materials ( Journal of Magnetism and Magnetic Materials ) 471 209 - 214 2019年02月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

High coercivity and resolution FePt•MgO-coated tip for imaging the magnetic field of perpendicular magnetic write head by alternating magnetic force microscopy (A-MFM)

Fu Zheng, Satoru Yoshimura, Shinya Yasui, Genta Egawa, and Hitoshi Saito

Journal of the Magnetics Society of Japan ( Journal of the Magnetics Society of Japan ) 43 ( 1 ) 6 - 10 2019年01月 [査読有り]

研究論文（学術雑誌）国内共著

High coercivity FePt•MgO films were successfully synthetized on cone-shape Si tips in a very high frequency (VHF) plasma irradiation-assisted magnetron sputtering system to prepare the MFM tips for evaluation of the AC magnetic field of perpendicular magnetic write head at high write current. Alloying with MgO significantly enhanced the coercivity of the magnetic coating due to the isolation of FePt grains by MgO. As a result, a high coercivity close to 20 kOe was achieved. The AC magnetic field images of the perpendicular magnetic write head at high write current were taken on alternating MFM (A-MFM) by this tip. A clear amplitude image with a strong signal at the main pole position was observe compared to the pure FePt layer-coated tip, which gave a blurry image and very small amplitude. Fourier analysis of the images obtained by this kind of FePt•MgO tip gives a spatial resolution of about 15 nm in air atmosphere. It is clear that the cone-shape FePt•MgO-coated MFM tip with a coercivity higher than the magnetic field to be measured is effective and capable for measuring the high AC magnetic field for an HD perpendicular magnetic write head at a very high write current.

DOI CiNii Research

High magnetization Co-GdOx superparamagnetic granular films as magnetic coating materials for high-sensitivity alternating magnetic force microscopy tip

Yongze Cao, Pawan Kumar, Yue Zhao, Yudai Suzuki, Satoru Yoshimura, Hitoshi Saito

Journal of Magnetism and Magnetic Materials ( Journal of Magnetism and Magnetic Materials ) 462 119 - 126 2018年09月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Fabrication of high-qualified (Bi1-xBax)FeO3 multiferroic thin films by using a pulsed DC reactive sputtering method and demonstration of magnetization reversal by electric field

Satoru Yoshimura, Munusamy Kuppan

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics ) 57 ( 9 ) 2018年09月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Magnetic energy flow imaging of magnetic recording head with enhanced resolution and sensitivity by A-MFM using high magnetic moment superparamagnetic tip

Pawan Kumar, Yongze Cao, Yudai Suzuki, Satoru Yoshimura, and Hitoshi Saito

Journal of Applied Physics ( Journal of Applied Physics ) 123 ( 21 ) 214503 2018年06月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Magnetic domain imaging of a very rough fractured surface of Sr ferrite magnet without topographic crosstalk by alternating magnetic force microscopy with a sensitive FeCo-GdOx superparamagnetic tip

Yongze Cao, Yue Zhao, Pawan Kumar, Satoru Yoshimura, and Hitoshi Saito

Journal of Applied Physics ( Journal of Applied Physics ) 123 ( 22 ) 224503 2018年06月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Active magnetic force microscopy of Sr-ferrite magnet by stimulating magnetization under an AC magnetic field: Direct observation of reversible and irreversible magnetization processes

Yongze Cao, Pawan Kumar, Yue Zhao, Satoru Yoshimura, and Hitoshi Saito

Applied Physics Letters ( Applied Physics Letters ) 112 ( 22 ) 223103 2018年05月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Magnetic domain structure imaging near sample surface with alternating magnetic force microscopy by using AC magnetic field modulated superparamagnetic tip

Yongze Cao, Shota Nakayama, Pawan Kumar, Yue Zhao, Yukinori Kinoshita, Satoru Yoshimura, Hitoshi Saito

Nanotechnology ( Nanotechnology ) 29 ( 30 ) 305502 2018年05月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Basic Study of Electric Field Induced Magnetization Reversal of Multiferroic (Bi1-xBax)FeO₃ Thin Films at Room Temperature for Magnetic Recording Technology

Satoru Yoshimura, Yusuke Sugawara, Genta Egawa, and Hitoshi Saito

Journal of the Magnetic Society of Japan ( 公益社団法人日本磁気学会 ) 42 ( 2 ) 11 - 14 2018年02月 [査読有り]

研究論文（学術雑誌）国内共著

(Bi1-xBax)FeO3 multiferroic thin films with ferromagnetism and ferroelectricity were fabricated and applied to create magnetic recordings using an electric field. The (001)-oriented (Bi1-xBax)FeO3 thin films of which electric polarization direction is perpendicular to the film plane were fabricated onto a non-single-crystalline substrate with a Ta seedlayer / (111)-oriented Pt underlayer at a low substrate temperature of 500 ℃. A very high frequency plasma irradiation was applied during sputtering deposition of (Bi1-xBax)FeO3 to accelerate the crystallization at the low substrate temperature. The fabricated (Bi0.6Ba0.4)FeO3 film exhibited hysteresis curves indicating ferromagnetic and ferroelectric behavior. The saturation magnetization of the film was approximately 60 emu/cm3 and the coercivity was approximately 2.5 kOe, respectively. Magnetic Force Microscopy analysis of the (Bi0.6Ba0.4)FeO3 film confirmed that the magnetization was reversed by applying only a local electric field. The multiferroic film described here is expected to be useful for electric field-driven magnetic devices.

DOI CiNii Research

AC Magnetic Field Imaging of Perpendicular Magnetic Write Head without Image Distortion on Alternating Magnetic Force Microscopy using a Cone-Shape FePt-coated Tip

Satoru Yoshimura, Fu Zheng, Shinya Yasui, Genta Egawa, and Hitoshi Saito

Journal of the Magnetic Society of Japan ( 公益社団法人日本磁気学会 ) 42 ( 1 ) 5 - 10 2018年01月 [査読有り]

研究論文（学術雑誌）国内共著

The AC magnetic field of a perpendicular magnetic write head having three surrounding shields was successfully imaged without image distortion on our alternating magnetic force microscope (A-MFM) using a newly developed cone-shape Si tip coated with an L10-FePt film. In contrast, a conventional quadrangular pyramidal Si tip coated with the L10-FePt film showed a distortion of the AC magnetic field image for the same magnetic write head. The image distortion depended on the spatial configuration between the tip and the write head. It is concluded that a round magnetic symmetry of the cone-shape FePt-coated tip is most effective for taking a clear AC magnetic field image of the perpendicular magnetic write head having three surrounding shields without distortion.

DOI CiNii Research

Magnetic resonance force microscopy using ferromagnetic resonance of a magnetic tip excited by microwave transmission via a coaxial resonator

Yukinori Kinoshita, Yan Jun Li, Satoru Yoshimura, Hitoshi Saito, and Yasuhiro Sugawara

Nanotechnology ( Nanotechnology ) 28 ( 48 ) 485709 2017年11月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

High resolution magnetic field energy imaging of the magnetic recording head by A-MFM with Co-GdOx super-paramagnetic tip

Pawan Kumar, Yudai Suzuki, Yongze Cao, Satoru Yoshimura, Hitoshi Saito

Applied Physics Letters ( Applied Physics Letters ) 111 ( 18 ) 183105 2017年10月 [査読有り]

研究論文（学術雑誌）国内共著

DOI

Low-energy mechanically milled τ-phase MnAl alloys with high coercivity and magnetization

Wei Lu, Junchao Niu, Taolei Wang, Kada Xia, Zhen Xiang, Yiming Song, Hong Zhang, Satoru Yoshimura, Hitoshi Saito

Journal of Alloys and Compounds 675 ( 5 ) 163 - 167 2016年12月 [査読有り]

研究論文（学術雑誌）国際共著

Quantitatively probing the magnetic behavior of individual nanoparticles by an AC field-modulated magnetic force microscopy

Xiang Li, Wei Lu, Yiming Song, Yuxin Wang, Aiying Chen, Biao Yan, Satoru Yoshimura, Hitoshi Saito

Scientific Reports 6 22467 2016年11月 [査読有り]

研究論文（学術雑誌）国内共著

High temperature exchange bias effect in melt-spun Mn55Bi45 alloys

Yiming Song, Zhen Xiang, Taolei Wang, Junchao Niu, Kada Xia, Wei Lu, Hong Zhang, Yongze Cao, Satoru Yoshimura and Hitoshi Saito

Applied Physics Letters 109 112402-1 - 112402-5 2016年10月 [査読有り]

研究論文（学術雑誌）国内共著

Exchange Springs in L10-FePt(110)/A1-FePt Bilayer Films

Y. H. Li, D. F. Zheng, H. J. Zhao, B. Du, J. Wei, S. Yoshimura, and H. Saito

IEEE TRANSACTIONS ON MAGNETICS 51 ( 11 ) 4800503 2015年10月 [査読有り]

研究論文（学術雑誌）国内共著

Pulsed magnetic field magnetic force microscope and evaluation of magnetic properties of soft magnetic tips

Y. Zheng, S. Yoshimura, G. Egawa, F. Zheng, Y. Kinoshita and H. Saito

Journal of Physics D: Applied Physics 48 335006 2015年08月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetic force microscopy using tip magnetization modulated by ferromagnetic resonance

E. Arima, Y. Naitoh, Y. J. Li, S. Yoshimura, H. Saito, H. Nomura, R. Nakatani, and Y. Sugawara

Nanotechnology 26 125701 2015年04月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetization behaviors of Fe3O4 nanoparticles studied by frequency-modulated magnetic force microscopy

X. Li, Z. Li, D. Pan, Z. Xiang, S. Yoshimura, and H. Saito

Materials Letters 125 36 - 39 2014年12月 [査読有り]

研究論文（学術雑誌）国内共著

Dynamic nanomagnetism characterization of individual magnetic nanoparticles by frequency-modulated magnetic force microscopy

X. Li, Z. Li, D. Pan, S. Yoshimura, and H. Saito

Applied Physics Letters 104 213106 2014年07月 [査読有り]

研究論文（学術雑誌）国内共著

A new method: study on individual magnetic nanoparticles by frequency-modulated magnetic force microscopy

X. Li, Z. Li, D. Pan, S. Yoshimura, and H. Saito

IEEE Transactions on Magnetics 58 ( 8 ) 6500404 2014年01月 [査読有り]

研究論文（学術雑誌）国内共著

Quantitative analysis of the magnetic domain structure in polycrystalline LaSrMnO thin films by magnetic force microscopy

Z. Li, F. Wei, S. Yoshimura, G. Li, H. Asano, H. Saito

Physical Chemistry Chemical Physics 52 ( 2 ) 628 - 633 2013年04月 [査読有り]

研究論文（学術雑誌）国内共著

Fabrication of high-coercivity FePt-MgO tip and its application to AC magnetic field imaging of perpendicular magnetic writing head by alternating magnetic force microscopy

F. Zheng, S. Yasui, G. Egawa, Y. Kinoshita, S. Yoshimura, and H. Saito

International Conference of Materials for Resources (ICMR, Akita, Japan, 2013) 239 - 243 2013年01月 [査読有り]

研究論文（学術雑誌）国内共著

周波数変調型磁気力顕微鏡を用いた磁気記録ヘッドの交流磁場観察－円錐形状FePt系高保磁力探針による像歪みの抑制－

吉村哲，安居慎也，江川元太，木下幸則，齊藤準

信学技報 112 ( 249 ) 53 - 59 2012年10月

研究論文（学術雑誌）国内共著

Alternating electric force microscopy: static electric field gradient imaging in an air atmosphere for Ba0.7Sr0.3TiO3 ferroelectric thin film

J. Lu, Y. Kinoshita, G. Egawa, S. Yoshimura, H. Asano, and H. Saito

Journal of Applied Physics 112 124110 2012年07月 [査読有り]

研究論文（学術雑誌）国内共著

Stroboscopic imaging of an alternating magnetic field from a perpendicular magnetic recording head by frequency-modulated magnetic force microscopy

Z. Li, K. Hatakeyama, G. Egawa, S. Yoshimura, and H. Saito

Applied Physics Letter 100 222405 2012年04月 [査読有り]

研究論文（学術雑誌）国内共著

Investigation on the microstructure and magnetic properties of FePt films prepared by sequentially sputtering

L. Zhang, Z. Li, X. Liu a, J. Bai, S. Yoshimura, H. Saito, F. Wei

Materials Letters 79 235 - 237 2012年01月 [査読有り]

研究論文（学術雑誌）国内共著

Fabrication of (001) oriented TMR film with highly ordered L10-Fe(Pd,Pt) alloy films by using a very thin Fe underlayer

S. Yoshimura, S. Omiya, G. Egawa, and H. Saito

IEEE Transactions on Magnetics 47 ( 10 ) 4417 - 4420 2011年10月 [査読有り]

研究論文（学術雑誌）国内共著

Simultaneous magnetic force microscopy imaging of perpendicular and in-plane magnetic field gradient on La0.7Sr0.3MnO3 granular film with in-plane magnetization

Z. Li, G. Egawa, S. Yoshimura, G. Li, H. Asano, and H. Saito

Journal of Applied Physics 109 07D334 2011年07月 [査読有り]

研究論文（学術雑誌）国内共著

Acceleration of ordering transformation of a new Fe2(Mn,Cr)Si Heusler-alloy film by VHF plasma irradiation process during RF sputter deposition

S. Yoshimura, H. Kobayashi, G. Egawa, H. Saito, and S. Ishida

Journal of Applied Physics 109 07B751 2011年07月 [査読有り]

研究論文（学術雑誌）国内共著

Direction detectable static magnetic field imaging by frequency-modulated magnetic force microscopy with an AC magnetic field driven soft magnetic tip

H. Saito, R. Ito, G. Egawa, Z. Li, and S. Yoshimura

Journal of Applied Physics 109 07E330 2011年07月 [査読有り]

研究論文（学術雑誌）国内共著

The role of symmetry-breaking-induced interface anisotropy in [Fe/Pt]n multilayer films

Z. Li, H. Xie, X. Liu, J. Bai, F. Wei, D. Wei, S. Yoshimura, H. Saito, and X.Liu

Journal of Applied Physics 109 07D343 2011年07月 [査読有り]

研究論文（学術雑誌）国内共著

Linearity of Giant Hall resistivity versus magnetic field in Fe/Pt/[CoFe/Pt]n/Fe/Pt multilayers

M. F. Liu, X. C. Song, H. Lv, L. R. Zhang, J. M. Bai, F. L. Wei, S. Yoshimura, and H. Saito

Journal of Physics: Conference Series 226 ( 1 ) 012003 2011年01月 [査読有り]

研究論文（学術雑誌）国内共著

Investigation of magnetic field effect on L10 FePt films during two-step tempering process

Y. B. Li, H. Lv, J. M. Bai, F. L. Wei, S. Yoshimura, and H. Saito

Journal of Physics: Conference Series 226 ( 1 ) 012017 2011年01月 [査読有り]

研究論文（学術雑誌）国内共著

MFM analysis of magnetic inhomogeneity in recorded area for perpendicular magnetic recording media by simultaneous imaging of perpendicular and in-plane magnetic field gradient

S. Yoshimura, S. Omiya, G. Egawa, H. Saito, and J. Bai

Journal of Physics: Conference Series 226 ( 1 ) 012065 2011年01月 [査読有り]

研究論文（学術雑誌）国内共著

Control of magnetic anisotropy field of (001) oriented L10-Fe(PdxPt1-x) films for MRAM application

S. Yoshimura, S. Omiya, G. Egawa, H. Saito, and J. Bai

Journal of Physics: Conference Series 226 ( 1 ) 012114 2011年01月 [査読有り]

研究論文（学術雑誌）国内共著

垂直磁気異方性制御が可能なL10型Fe(PdxPt1-x)合金を用いたスピン注入書き込みMRAM用FePt基TMR積層膜の作製

大宮翔吾，吉村哲，江川元太，齊藤準

信学技報 110 ( 225 ) 31 - 36 2010年10月

研究論文（学術雑誌）国内共著

High resolution magnetic imaging of perpendicular magnetic recording head using frequency-modulated magnetic force microscopy with a hard magnetic tip

W. Lu, Z. Li, K. Hatakeyama, G. Egawa, S. Yoshimura, and H. Saito

Applied Physics Letter 96 143104 2010年01月 [査読有り]

研究論文（学術雑誌）国内共著

High frequency magnetic field imaging by frequency modulated magnetic force microscopy

H. Saito, W. Lu, K. Hatakeyama, G. Egawa, and S. Yoshimura

Journal of Applied Physics 107 09D309 2010年01月 [査読有り]

研究論文（学術雑誌）国内共著

Characterization of Magnetic Field Distribution in a Trailing-Edge Shielded Head by Frequency-Modulated Magnetic Force Microscopy

W. Lu, K. Hatakeyama, G. Egawa, S. Yoshimura, and H. Saito

IEEE Transactions on Magnetics 46 ( 6 ) 1479 - 1482 2010年01月 [査読有り]

研究論文（学術雑誌）国内共著

High resolution MFM imaging of in-plane magnetic field gradients using transient oscillation for perpendicular magnetic recording media

G. Egawa, S. Yoshimura, T. Miyazawa, G. Li, and H. Saito

International Conference of Materials for Resources (ICMR, Akita, Japan, 2009) 345 - 349 2009年10月 [査読有り]

研究論文（学術雑誌）国内共著

Bistable control of ferromagnetic resonance frequencies in ferromagnetic trilayered dots

Y. Nozaki, K. Tateishi, S. Taharazako, S. Yoshimura, and K. Matsuyama

Journal of Applied Physics 105 13911 2009年01月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetic force microscopy of alternating magnetic field by frequency modulation of tip oscillation

H. Saito, H. Ikeya, G. Egawa, S. Ishio, and S. Yoshimura

Journal of Applied Physics 105 07D524 2009年01月 [査読有り]

研究論文（学術雑誌）国内共著

磁気力顕微鏡を用いた垂直磁気記録媒体の高分解能・面内磁場勾配イメージング

齊藤準，宮澤翼，江川元太，石尾俊二，吉村哲

信学技報 108 ( 234 ) 31 - 35 2008年10月

研究論文（学術雑誌）国内共著

Heat-assisted magnetization reversal using pulsed laser irradiation in patterned magnetic thin film with perpendicular anisotropy

K. Waseda, R. Doi, B. Purnama, S. Yoshimura, Y. Nozaki, and K. Matsuyama

IEEE Transactions on Magnetics 44 ( 11 ) 2483 - 2486 2008年07月 [査読有り]

研究論文（学術雑誌）国内共著

Co基ホイスラー合金を用いたGMR積層膜の作製

渡邊義典, 宍倉千恵子, 吉村哲, 浅野秀文, 松井正顯

Journal of the Magnetics Society of Japan (日本磁気学会誌) 32 ( 3 ) 308 - 311 2008年03月 [査読有り]

研究論文（学術雑誌）国内共著

Fe2Cr1-xTixSi ホイスラー合金の構造と磁性

山地一史, 中村泰貴, 竹田陽一, 吉村哲, 浅野秀文, 松井正顯, 石田尚治

Journal of the Magnetics Society of Japan (日本磁気学会誌) 32 ( 3 ) 325 - 328 2008年03月 [査読有り]

研究論文（学術雑誌）国内共著

Influence of interlayer magnetostatic coupling on the ferromagnetic resonance properties of lithographically patterned ferromagnetic trilayers

Y. Nozaki, K. Tateishi, S. Taharazako, S. Yoshimura, and K. Matsuyama

Applied Physics Letter 92 161903 2008年01月 [査読有り]

研究論文（学術雑誌）国内共著

非単結晶基板上における(100)高配向Co2MnGe薄膜及びそれを用いた強磁性トンネル接合の作製

高野雅志, 吉村哲, 竹田陽一, 浅野秀文, 松井正顯

Journal of the Magnetics Society of Japan (日本磁気学会誌) 32 ( 1 ) 40893 2008年01月 [査読有り]

研究論文（学術雑誌）国内共著

Crystalline structure and magnetic property of Fe2CrSi Heusler alloy films - New ferromagnetic material for high performance MRAM -

S. Yoshimura, H. Asano, Y. Nakamura, K. Yamaji, Y. Takeda, M. Matsui, S. Ishida, Y. Nozaki, and K. Matsuyama

Journal of Applied Physics 103 07D716 2008年01月 [査読有り]

研究論文（学術雑誌）国内共著

Microwave-assisted magnetization reversal in 0.36-m-wide Permalloy wires

Y. Nozaki, S. Taharazako, K. Tateishi, M. Ohta, S. Yoshimura, and K. Matsuyama

Applied Physics Letter 91 122505 2007年12月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetic force microscopy study of microwave-assisted magnetization reversal in submicron-scale ferromagnetic particles

Y. Nozaki, M. Ohta, S. Taharazako, K. Tateishi, S. Yoshimura, and K. Matsuyama

Applied Physics Letter 91 82510 2007年12月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of crystallographic orientation of Co2MnGe Heusler-alloy film on its surface roughness and ordered structure

Y. Takeda, S. Yoshimura, M. Takano, H. Asano, and M. Matsui

Journal of Applied Physics 101 09J514 2007年05月 [査読有り]

研究論文（学術雑誌）国内共著

高キュリー温度Sr2CrReO6薄膜のXPS観察

高橋佑介, 吉村哲, 浅野秀文, 松井正顯

Journal of the Magnetics Society of Japan (日本応用磁気学会誌) 31 ( 3 ) 193 - 198 2007年04月 [査読有り]

研究論文（学術雑誌）国内共著

微細加工されたLa0.7Sr0.3MnO3薄膜のアニールによる回復効果

二井優行, 岡武宏, 吉村哲, 浅野秀文, 松井正顯

Journal of the Magnetics Society of Japan (日本応用磁気学会誌) 31 ( 4 ) 333 - 337 2007年04月 [査読有り]

研究論文（学術雑誌）国内共著

Low-temperature transformation and electronic structure of (Ni1−xCox)2MnGa

Y. Takeda, K. Kodera, S. Yoshimura, H. Asano, and M. Matsui

Journal of Magnetism and Magnetic Materials 310 1838 - 1840 2007年02月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of buffer layer and seedlayer materials on control of crystallographic orientation of Co2MnGe layer onto a thermally oxidized Si wafer

S. Yoshimura, M. Takano, Y. Takeda, H. Asano, and M. Matsui

Journal of Magnetism and Magnetic Materials 310 1978 - 1980 2007年02月 [査読有り]

研究論文（学術雑誌）国内共著

Oxidation Process of Mg Films by Using High Concentration Ozone for Magnetic Tunnel Junctions

S. Yoshimura, Y. Narisawa, Y. Watanabe, M. Tsunoda, and M. Takahashi

Journal of Magnetism and Magnetic Materials 312 176 - 180 2007年01月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetization switching of CoFeSiB free-layered magnetic tunnel junctions

B. S. Chun, J. Y. Hwang, J. R. Rhee, T. Kim, S. Saito, S. Yoshimura, M. Tsunoda, M. Takahashi, and Y. K. Kim

Journal of Magnetism and Magnetic Materials 303 e223 - e225 2006年01月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetization switching of NiFeSiB free layers for magnetic tunnel junctions

B. S. Chun, S. P. Ko, B. S. Oh, J. Y. Hwang, J. R. Rhee, T. W. Kim, S. Saito, S. Yoshimura, M. Tsunoda, M. Takahashi, and Y. K. Kim

Journal of Magnetism and Magnetic Materials 304 e258 - e260 2006年01月 [査読有り]

研究論文（学術雑誌）国内共著

The switching characteristics of free layer of patterned magnetic tunnel junction device

C. C. Chen, Y. R. Wang, C. Y. Kuo, J. C. Wu, L. Horng, T. Wu, S. Yoshimura, M. Tsunoda, and M. Takahashi

Journal of Magnetism and Magnetic Materials 304 e285 - e287 2006年01月 [査読有り]

研究論文（学術雑誌）国内共著

高濃度オゾン酸化法による金属Al膜の酸化過程とそれを用いて作製した強磁性トンネル接合膜の磁気抵抗効果

吉村哲, 成澤洋祐, 角田匡清, 高橋研

Journal of the Magnetics Society of Japan (日本応用磁気学会誌) 29 ( 8 ) 820 - 825 2005年08月 [査読有り]

研究論文（学術雑誌）国内共著

トンネル接合膜のTMR特性に及ぼすAl-N絶縁層へのイオン照射の効果

角田匡清, 渡辺義彦, 今北健一, 吉村哲, 高橋研

Journal of the Magnetics Society of Japan (日本応用磁気学会誌) 29 ( 6 ) 653 - 657 2005年06月 [査読有り]

研究論文（学術雑誌）国内共著

Surface flattening processes of metal layer and their effect on transport properties of magnetic tunnel junctions with Al-N barrier

S. Yoshimura, T. Nozawa, T. Shoyama, M. Tsunoda, and M. Takahashi

Journal of Applied Physic 97 10C920 2005年05月 [査読有り]

研究論文（学術雑誌）国内共著

Radical nitridation of Al films for the barrier formation in ferromagnetic tunnel junctions

M. Tsunoda, T. Shoyama, S. Yoshimura, and M. Takahashi

Journal of Magnetism and Magnetic Materials 286 162 - 166 2005年01月 [査読有り]

研究論文（学術雑誌）国内共著

Nitridation process of Al layer by microwave-excited plasma and large magnetoresistance in Co-Fe / Al-N / Co-Fe tunnel junctions

S. Yoshimura, T. Shoyama, T. Nozawa, M. Tsunoda, and M. Takahashi

IEEE Transactions on Magnetics 40 ( 4 ) 2290 - 2292 2004年01月 [査読有り]

研究論文（学術雑誌）国内共著

強磁性トンネル接合用Al薄膜の酸化過程とマイクロ波励起プラズマ中の酸化種との相関

吉村哲, 角田匡清, 尾形聡, 高橋研

Journal of the Magnetics Society of Japan (日本応用磁気学会誌) 27 ( 12 ) 1130 - 1134 2003年12月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of Naturally Adsorbed Gas on Substrate Surface on the Growth of Very Thin WCr Seedlayer

S. Yoshimura, D. D. Djayaprawira, Y. Takakuwa, and M. Takahashi

IEEE Transactions on Magnetics 39 ( 5 ) 2270 - 2272 2003年07月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of Oxidation Process on Grain Size Reduction for Longitudinal Media Using Ni-baced Amorphous Seedlayer

M. Mikami, D. D. Djayaprawira, S. Yoshimura, and M. Takahashi

IEEE Transactions on Magnetics 39 ( 5 ) 2258 - 2261 2003年07月 [査読有り]

研究論文（学術雑誌）国内共著

The Effect of Very Thin Cr-based Seedlayer Material with Different Affinity for Oxygen on Thin Film Media Microstructure and Recording Properties

S. Yoshimura, D. D. Djayaprawira, Y. Takakuwa, and M. Takahashi

Journal of Applied Physics 93 ( 10 ) 8465 - 8467 2003年04月 [査読有り]

研究論文（学術雑誌）国内共著

Improvement of Exchange Bias Field by Introduction of Oxygen During Deposition of Ru Layer in Antiferromagnetic Coupled Media

D. D. Djayaprawira, H. Domon, S. Yoshimura, and M. Takahashi

Journal of Applied Physics 93 ( 10 ) 7408 - 7410 2003年04月 [査読有り]

研究論文（学術雑誌）国内共著

薄膜磁気記録媒体における諸特性の極薄Cr基シード層組成依存性（Cr基シード層の成長様式及び融点・酸素親和性と媒体の微細構造との関係）

吉村哲, D. D. Djayaprawira, 三上正樹, 高桑雄二, 高橋研

日本応用磁気学会誌 27 ( 4 ) 234 - 240 2003年01月 [査読有り]

研究論文（学術雑誌）国内共著

Control of thin film medis microstructure by using very thin seedlayer material with different affinity for oxygen

D. D. Djayaprawira, S. Yoshimura, and M. Takahashi

Journal of Magnetics 73 ( 3 ) 106 - 114 2002年12月 [査読有り] [招待有り]

研究論文（学術雑誌）国内共著

Dependence of thin film media microstructure and recording properties on composition of very thin Cr-based seedlayer

S. Yoshimura, D. D. Djayaprawira, M. Mikami, Y. Takakuwa, and M. Takahashi

IEEE Transactions on Magnetics 38 ( 5 ) 1958 - 1960 2002年10月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetic Grain Size Reduction by Using Oxygen Exposure Process onto Very Thin WCr Seedlayer in Longitudinal Media

S. Yoshimura, D. D. Djayaprawira, M. Mikami, M. Takahashi, K. Komiyama, A. Horii, A. Ohno, and S. Katayama

Journal of Applied Physics 91 ( 10 ) 8629 - 8631 2002年04月 [査読有り]

研究論文（学術雑誌）国内共著

Study on Increasing Coercivity in CoCrPtB Media with High Pt Content

M. Mikami, D. D. Djayaprawira, H. Domon, S. Yoshimura, M. Takahashi, and K. Komiyama

Journal of Applied Physics 91 ( 10 ) 7074 - 7076 2002年04月 [査読有り]

研究論文（学術雑誌）国内共著

Dependence of Exchange Bias Field on Composition of Stabilizing Layer and Sputtering Process in Synthetic Ferrimagnetic Coupled Media

D. D. Djayaprawira, K. Komiyama, S. Yoshimura, T. Michalke, and M. Takahashi

Journal of Magnetism and Magnetic Materials 239 396 - 398 2002年03月 [査読有り]

研究論文（学術雑誌）国内共著

Correlation between Activation Volume and Intergranular Magnetic Interaction in Longitudinal Media

M. Mikami, D. D. Djayaprawira, Tham Kim Kong, S. Yoshimura, A. Horii, and M. Takahashi

IEEE Transactions on Magnetics 37 ( 4 ) 1484 - 1486 2001年10月 [査読有り]

研究論文（学術雑誌）国内共著

Improvement of Magnetic and R/W Properties in Longitudinal Media by Using CrX/Cr Dual Underlayer

D. D. Djayaprawira, A. Horii, K. Komiyama, S. Yoshimura, M. Mikami, H. Domon, and M. Takahashi

IEEE Transactions on Magnetics 37 ( 4 ) 1497 - 1499 2001年10月 [査読有り]

研究論文（学術雑誌）国内共著

極薄高融点WCrシード層による薄膜磁気記録媒体の結晶粒微細化（高Hkgrain媒体における低ノイズ化）

S. Yoshimura, D. D. Djayaprawira, A. Horii, M. Mikami, H. Shoji, and M. Takahashi

日本応用磁気学会誌 25 ( 40635 ) 627 - 630 2001年04月 [査読有り]

研究論文（学術雑誌）国内共著

Novel Sputtering Process to Reduce The Grain Size and Its Distribution In Co-based Longitudinal Thin Film Media (New Seedlayer and High Kugrain Materials)

M. Takahashi, H. Shoji, D. D. Djayaprawira, and S. Yoshimura

IEEE Transactions on Magnetics 36 ( 5 ) 2315 - 2320 2000年10月 [査読有り] [招待有り]

研究論文（学術雑誌）国内共著

Media Noise Reduction In Co-based Longitudinal Media with New Co co-precipitated NiP/Al Substrate

S. Yoshimura, D. D. Djayaprawira, Tham Kim Kong, Y. Masuda, H. Shoji, and M. Takahashi

IEEE Transactions on Magnetics 36 ( 5 ) 2363 - 2365 2000年10月 [査読有り]

研究論文（学術雑誌）国内共著

Challenge to a Physical Limit in Longitudinal High Density Recording Media

M. Takahashi, H. Shoji, S. Yoshimura, and D. D. Djayaprawira

Electrochemical Society Proceedings 99 ( 34 ) 273 - 285 2000年08月 [査読有り] [招待有り]

研究論文（学術雑誌）国内共著

Grain Size Reduction by Utilizing Very Thin CrW Seedlayer and Dry-Etching Process in CoCrTaNiPt Longitudinal Media

S. Yoshimura, D. D. Djayaprawira, Tham Kim Kong, Y. Masuda, H. Shoji, and M.Takahashi

Journal of Applied Physics 87 ( 9 ) 6860 - 6862 2000年01月 [査読有り]

研究論文（学術雑誌）国内共著

Magnetic and Structural Properties of CoCrTaNiPt Longitudinal Thin Film Media

S. Yoshimura, D. D. Djayaprawira, H. Shoji, and M. Takahashi

Journal of Applied Physics 87 ( 9 ) 6866 - 6868 2000年01月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of Pt on the Intergranular Exchange Coupling in CoCrTaPt Thin Film Media Prepared under Ultra Clean Sputtering Process

M. Takahashi, H. Hara, A. Kikuchi, S. Yoshimura, and H. Shoji

Journal of the Magnetics Society of Japan 23 335 - 337 1999年01月 [査読有り]

研究論文（学術雑誌）国内共著

Effect of Film Thickness on Magnetic Properties and Microstructure for CoCrTa Media Prepared under Ultra Clean Sputtering Process

M. Takahashi, A. Kikuchi, N. Iwata, S. Yoshimura, K. K. Tham, and H. Shoji

Journal of the Magnetics Society of Japan 23 739 - 741 1999年01月 [査読有り]

研究論文（学術雑誌）国内共著

　前のページ - 次のページ　

<吉村 哲>

研究等業績 - 原著論文 - 吉村 哲

<吉村　哲>

研究等業績 - 原著論文 - 吉村　哲