Research Achievements - Original paper -

Formation of a body-centered tetragonal structure with high magnetic anisotropy and coercivity in Fe–Co–V films with high C contents

T. Hasegawa, T. Nishikawa, C. Shirai

IEEE Transactions on Magnetics   59 ( 11 ) 2100905-1 - 2100905-5   2023.06  [Refereed]

Research paper (journal)   Domestic Co-author

Perpendicular magnetic properties on hcp-Co80Pt20 stacked films with oxide seed layers

Journal of the Japan Institute of Metals and Materials   87 ( 4 ) 139 - 147   2023.04  [Refereed]

Research paper (journal)   Domestic Co-author

Body-centered tetragonal structure in Fe-Co-V-N bulk foils fabricated by rolling and ammonia-gas-nitriding method

T. Hasegawa

Scientific Reports   13   5666-1 - 5666-8   2023.04  [Refereed]

Research paper (journal)   Single author

Polarization transformation and destructive interference on subwavelength magnetic domains in magneto‑plasmonic systems

H. Yamane, S. Yanase, T. Hasegawa, M. Kobayashi, Y. Yasukawa

Scientific Reports   12   13871-1 - 13871-10   2022.08  [Refereed]

Research paper (journal)   Domestic Co-author

TEM-based crystal structure analysis of body-centered tetragonal structure in non-epitaxial FeCo film with added V and N

T. Hasegawa, Y. Seki

Materials Letters   313   131734-1 - 131734-3   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

Effect of V addition on the body-centered cubic to body-centered tetragonal to face-centered cubic structural transformation of N-containing Fe and FeCo films

T. Hasegawa, C. Shirai

Thin Solid Films   739   138990-1 - 138990-5   2021.11  [Refereed]

Research paper (journal)   Domestic Co-author

Challenges toward development of rear-earth free FeCo based permanent magnet

T. Hasegawa

Electronics and Communications in Japan   104 ( 2 ) 1 - 8   2021.03  [Refereed]  [Invited]

Research paper (journal)   Single author

MFM observation of high coercivity in nanostructured tetragonally distorted FeCo films

T. Hasegawa, Le Duy Long, Y. Nakamura

IEEE Transactions on Magnetics   57 ( 2 ) 6500105-1 - 6500105-5   2020.07  [Refereed]

Research paper (journal)   Domestic Co-author

TEM observation of nitrogen-tunable bcc-bct-fcc transformation of iron-cobalt with added vanadium

T. Hasegawa, C. Shirai, Y. Takemasa, Y. Seki

AIP Advances   10   015110-1 - 015110-5   2020.01  [Refereed]

Research paper (journal)   Domestic Co-author

Stabilisation of tetragonal FeCo structure with high magnetic anisotropy by the addition of V and N elements

T. Hasegawa, T. Niibori, Y. Takemasa, M. Oikawa

Scientific Reports   9   5248-1 - 5248-9   2019.03  [Refereed]

Research paper (journal)   Domestic Co-author

Development of high density magnetic recording media

T. Hasegawa

The Journal of the Institute of Electrical Engineers of Japan (IEEJ Journal)   139 ( 1 ) 14 - 17   2019.01  [Invited]

Research paper (journal)   Single author

Fabrication and magnetization reversal of L10 FeMnPt dots surrounded by paramagnetic A1 phase formed by ion irradiation

T. Hasegawa, K. Sasaki, C. W. Barton, T. Thomson

Scripta Materialia   142   6 - 9   2018.04  [Refereed]

Research paper (journal)   International Co-author

Uniaxial magnetic anisotropy of tetragonal FeCoV and FeCoVC films

K. Takahashi, M. Sakamoto, K. Kumagai, T. Hasegawa, and S. Ishio

Journal of Physics D: Applied Physics   51 ( 6 ) 065005-1 - 065005-9   2018.04  [Refereed]

Research paper (journal)   Domestic Co-author

Conversion of FeCo from soft to hard magnetic material by lattice engineering and nanopatterning

T. Hasegawa, S. Kanatani, M. Kazaana, K. Takahashi, K. Kumagai, M. Hirao, S. Ishio

Scientific Reports   7   13215-1 - 13215-7   2017.10  [Refereed]

Research paper (journal)   Domestic Co-author

Structural dependent ferromagnetic-nonmagnetic phase change in FePtRu films

T. Hasegawa, K. Ito

Advances in Materials Science and Engineering   2017   8949458-1 - 8949458-7   2017.07  [Refereed]  [Invited]

Research paper (journal)   Domestic Co-author

Structural control of ultra-fine CoPt nanodot arrays via electrodeposition process

S. Wodarz, T. Hasegawa, S. Ishio, T. Homma

Journal of Magnetism and Magnetic Materials   430   52 - 58   2017.05  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Uniaxial magnetic anisotropy of tetragonal FeCo based alloy films

S. Ishio, T. Hasegawa, S. Yoshida, S. Kanatani, K. Takahashi, K. Kumagai, M. Hirao

Magnetics Japan   12 ( 1 ) 21 - 25   2017.02  [Invited]

Research paper (journal)   Domestic Co-author

Correlation between crystal planes and disordering of ordered L10 FePt structure caused by ion irradiation

T. Hasegawa, T. Yamazaki, and S. Ishio

Materials Letters   178   243 - 247   2016.05  [Refereed]

Research paper (journal)   Domestic Co-author

Microstructure of L10 FePt thin films with anisotropic interfacial energy coefficients and anisotropic atomic mobilities

L. Liu, L. Zhang, L. Liang, K. Ohsasa, T. Koyama, Q. Sheng, T. Hasegawa, S. Ishio

Journal of Alloys and Compounds   682   176 - 179   2016.04  [Refereed]

Research paper (journal)   Domestic Co-author

Microfabrication of FeMnPt films involving magnetic phase change due to structural transformation caused by ion irradiation

T. Hasegawa, R. Kasahara, K. Sasaki, and S. Ishio

Physica Status Solidi - Rapid Research Letters   10 ( 6 ) 498 - 502   2016.04  [Refereed]

Research paper (journal)   Domestic Co-author

Studying the ferromagnetic-paramagnetic phase transition in thin films of L10 FePt1-xRhx

A. A. Valiullin, A. S. Kamzin, S. Ishio, T. Hasegawa, V. R. Ganeev, L. R. Tagirov, and L. D. Zaripova

Bulletin of the Russian Academy of Sciences. Physics   79 ( 8 ) 999 - 1001   2015.08  [Refereed]

Research paper (journal)   Domestic Co-author

Tetragonally distorted structure and uniaxial magnetic anisotropy of Fe100-xCox/Rh/MgO epitaxial films

H. Oomiya, B. Wang, S. Yoshida, T. Kataguchi, K. Takahashi, S. Kanatani, L. Zhang, L. Liu, T. Hasegawa, K. Hayasaka, S. Saito, N. Inami, T. Ueno, K. Ono, and S. Ishio

Journal of Physics D: Applied Physics   48 ( 47 ) 475003-1 - 475003-6   2015.03  [Refereed]

Research paper (journal)   Domestic Co-author

Correlation between magnetic phase transition temperatures and lattice distortions in L10 FePtRh thin films

Journal of the Japan Institute of Metals and Materials   79 ( 9 ) 423 - 428   2015.02  [Refereed]

Research paper (journal)   Domestic Co-author

Investigation of magnetic anisotropy and magnetic moments of tetragonal distorted Fe1-xCox films on L10 FePt underlayer

B. Wang, H. Oomiya, A. Arakawa, T. Hasegawa, H. Sasaki, and S. Ishio

Journal of Applied Physics   117 ( 17 ) 17C709-1 - 17C709-4   2015.01  [Refereed]

Research paper (journal)   Domestic Co-author

Nanoscale composition control applied on L10 FePtRh film for dot patterning using magnetic phase change

T. Hasegawa, Y. Kondo, K. Uebayashi, A. Arakawa, and S. Ishio

IEEE Transactions on Magnetics   50 ( 11 ) 2302004-1 - 2302004-4   2014.05  [Refereed]

Research paper (journal)   Domestic Co-author

Fabrication of dot pattern using magnetic phase change on Pt ion-implanted L10 FePtRh film with high magnetocrystalline anisotropy

T. Hasegawa, T. Yamazaki, Y. Kondo, and S. Ishio

Journal of Applied Physics   115 ( 17 ) 17B721-1 - 17B721-3   2014.04  [Refereed]

Research paper (journal)   Domestic Co-author

Perpendicular magnetic anisotropy and magnetization of L10 FePt/FeCo bilayer films

B. Wang, H. Oomiya, A. Arakawa, T. Hasegawa, and S. Ishio

Journal of Applied Physics   115 ( 13 ) 133908-1 - 133908-5   2014.03  [Refereed]

Research paper (journal)   Domestic Co-author

Switching field distribution and magnetization reversal process of FePt dot patterns

S. Ishio, S. Takahashi, T. Hasegawa, A. Arakawa, H. Sasaki, Z. Yan, X. Liu, Y. Kondo, H. Yamane, J. Ariake, M. Suzuki, N. Kawamura, and M. Mizumaki

Journal of Magnetism and Magnetic Materials   360   205 - 210   2014.02  [Refereed]

Research paper (journal)   Domestic Co-author

Towards an understanding of microstructure of patterned FePt dots by magnetometry using pulse fields

Z. J. Yan, S. Takahashi, T. Hasegawa, S. Ishio, Y. Kondo, and J. Ariake

Journal of Magnetism and Magnetic Materials   349   5 - 8   2014.01  [Refereed]

Research paper (journal)   Domestic Co-author

Magnetic phase diagram and crystalline structure of polycrystalline FeMnPt films

Journal of the society of materials engineering for resources of Japan   25 ( 1/2 ) 5 - 12   2013.04  [Refereed]

Research paper (journal)   Domestic Co-author

Ferromagnetic-paramagnetic patterning of FePtRh films by Fe ion implantation

T. Hasegawa, Y. Kondo, H. Yamane, S. Nagamachi, and S. Ishio

IEEE Trans Magn   49 ( 7 ) 3604 - 3607   2013.04  [Refereed]

Research paper (journal)   Domestic Co-author

Understanding magnetic properties of arrays of small FePt dots with perpendicular anisotropy

Z. J. Yan, S. Takahashi, T. Hasegawa, S. Ishio, Y. Kondo, J. Ariake, and D. S. Xue

Journal of Magnetism and Magnetic Materials   324   3737 - 3740   2012.06  [Refereed]

Research paper (journal)   Domestic Co-author

Fabrication of [001] L10-FePtRh ferro-antiferromagnetic pattern by flat-patterning method

T. Hasegawa, T. Tomioka, Y. Kondo, H. Yamane, and S. Ishio

Journal of Applied Physics   111 ( 7 ) 07B903-1 - 07B903-3   2012.02  [Refereed]

Research paper (journal)   Domestic Co-author

L10 FePt thin films with [001] crystalline growth fabricated by SiO2 addition-rapid thermal annealing and dot patterning of the films

S. Ishio, T. Narisawa, S. Takahashi, Y.E. Kamata, S. Shibata and T. Hasegawa, Z. Yan, H. Yamane, Y. Kondo and J. Ariake

Journal of Magnetism and Magnetic Materials   324   295 - 302   2012.01  [Refereed]  [Invited]

Research paper (journal)   Domestic Co-author

Geometric and magnetic properties of L10 FePtRh ferro-antiferromagnetic pattern fabricated by flat-patterning method using atomic diffusion

Journal of the Magnetics Society of Japan   36 ( 2 ) 104 - 108   2012.01  [Refereed]

Research paper (journal)   Domestic Co-author

Study on nanoscale patterning using ferro-antiferromagnetic transition in [001]-oriented L1₀ FePtRh film

T. Hasegawa, T. Tomioka, Y. Kondo, H. Yamane, and S. Ishio

Journal of Applied Physics   109 ( 7 ) 07B705-1 - 07B705-3   2011.03  [Refereed]

Research paper (journal)   Domestic Co-author

Incoherent magnetization reversal in Co-Pt nanodots investigated by magnetic force microscopy

W.L. Pei, G.W. Qin, Y.P. Ren, S. Li, T. Wang, T. Hasegawa, S. Ishio, H. Yamane

Acta Materialia   59   4818 - 4824   2011.03  [Refereed]

Research paper (journal)   Domestic Co-author

[001]-oriented nonepitaxial growth in L10-ordered FePt thin film by SiO2 addition and rapid thermal annealing

T. Narisawa, T. Hasegawa, S. Ishio, H. Yamane

Journal of Applied Physics   109 ( 3 ) 033918-1 - 033918-7   2011.02  [Refereed]

Research paper (journal)   Domestic Co-author

Structural characterization for L10-ordered FePt films with (001) texture by x-ray diffraction with (001) texture by x-ray diffraction

H. Yamane, T. Narisawa, T. Hasegawa, S. Ishio

Journal of Applied Physics   108 ( 11 ) 113923-1 - 113923-8   2010.12  [Refereed]

Research paper (journal)   Domestic Co-author

Fabrication of Co-Pt dot array with 1 Tdot/in2 for bit patterned media by low energy ion etching

  34 ( 4 ) 484 - 488   2010.04  [Refereed]

Research paper (journal)   Domestic Co-author

Study of ferro-antiferromagnetic transition in [001]-oriented L1₀ FePt_1-xRh_x film

T. Hasegawa, J. Miyahara, T. Narisawa, S. Ishio, H. Yamane, Y. Kondo, J. Ariake, S. Mitani, Y. Sakuraba, and K. Takanashi

Journal of Applied Physics   106 ( 10 ) 103928-1 - 103928-6   2009.11  [Refereed]

Research paper (journal)   Domestic Co-author

Tuning interlayer coupling and domain structure in [Co/Pd]n Co/Ru [Co/Pd (x)]m multilayer by controlling the thickness x of the weak-ferromagnetic Pd layers in the lower Co/Pd multilayer

Y. Fu, S. Ishio, T. Wang, W. Pei, T. Hasegawa, H. Yamane, H. Saito

Journal of Applied Physics   105 ( 7 ) 07C307-1 - 07C307-3   2009.03  [Refereed]

Research paper (journal)   Domestic Co-author

A magnetic force microscopy study of the magnetic reversal of a single Fe nanowire

T. Wang, Y. Wang, Y. Fu, T. Hasegawa, F. S. Li, H. Saito, S. Ishio

Nanotechnology   20 ( 10 ) 105707-1 - 105707-5   2009.02  [Refereed]

Research paper (journal)   Domestic Co-author

Magnetic behavior in an ordered Co nanorod array

T. Wang, Y. Wang, Y. Fu, T. Hasegawa, H. Oshima, K. Itoh, K. Nishio, H. Masuda, F. S. Li, H. Saito, S. Ishio

Nanotechnology   19 ( 45 ) 455703-1 - 455703-6   2008.10  [Refereed]

Research paper (journal)   Domestic Co-author

Magnetization reversal of Co/Cu/Co elliptical elements studied by in-field magnetic force microscope and micromagnetic simulation

T. Wang, W. Pei, Y. Fu, T. Washiya, T. Hasegawa, H. Saito, S. Ishio, Y. Wang, F.S.Li, J. Ariake

Journal of Applied Physics   103 ( 9 ) 093910-1 - 093910-4   2008.05  [Refereed]

Research paper (journal)   Domestic Co-author

In-field magnetic force microscope study of dipolar interaction in an ideally ordered Co nanorod array fabricated using nanoimprint lithography

T. Wang, Y. Wang, Y. Fu, T. Hasegawa, T. Washiya, H. Saito, S. Ishio, F.S.Li, H. Oshima, K. Itoh, K. Nishio, H. Masuda

Applied Physics Letters   92 ( 19 ) 192504-1 - 192504-3   2008.05  [Refereed]

Research paper (journal)   Domestic Co-author

Study on magnetization reversal of cobalt nanowire arrays by magnetic force microscopy

J. Yuan, W. Pei, T. Hasagawa, T. Washiya, H. Saito, S. Ishio, H. Oshima, K. Itoh

Journal of Magnetism and Magnetic Materials   320 ( 5 ) 736 - 741   2008.03  [Refereed]

Research paper (journal)   Domestic Co-author

MFM analysis of the magnetization process in L1₀-A1 FePt patterned film fabricated by ion irradiation

T. Hasegawa, W. Pei, T. Wang, Y. Fu, T. Washiya, H. Saito, and S. Ishio

Acta Materialia   56 ( 7 ) 1564 - 1569   2008.01  [Refereed]

Research paper (journal)   Domestic Co-author

Magnetization reversal in Co/Pt multilayer with weak intergranular coupling

T. Wang, W. Pei, Y. Fu, T. Hasegawa, T. Washiya, H. Saito, S. Ishio, Y. Wang, and F. S. Li

Journal of Applied Physics   102 ( 12 ) 123909-1 - 123909-4   2007.12  [Refereed]

Research paper (journal)   Domestic Co-author

Influence of synthetic conditions on iron oxide nanoparticles

W. Pei, Y. Fu, H. Kumada, T. Wang, T. Hasegawa, T. Washiya, H. Saito, S. Ishio

Physica status solidi (a)   204 ( 12 ) 4017 - 4020   2007.12  [Refereed]

Research paper (journal)   Domestic Co-author

Magnetic field dependent behavior in perpendicular antiferromagnetically coupled multiplayer films

Y. Fu, J. Yuan, T. Wang, T. Hasegawa, T. Washiya, H. Saito, S. Ishio

Applied Physics Letters   91 ( 15 ) 152505-1 - 152505-3   2007.10  [Refereed]

Research paper (journal)   Domestic Co-author

Study on magnetization reversal of perpendicular recording media by in-field MFM observation

W. Pei, J. Yuan, T. Wang, Y. Fu, T. Washiya, T. Hasegawa, H. Saito, S. Ishio, and N. Honda

Acta Materialia   55 ( 9 ) 2959 - 2964   2007.02  [Refereed]

Research paper (journal)   Domestic Co-author

Structural transition from L1₀ phase to A1 phase in FePt films caused by ion irradiation

T. Hasegawa, G. Q. Li, W. Pei, H. Saito, S. Ishio, K. Taguchi, K. Yamakawa, N. Honda, K. Ouchi, T. Aoyama, and I. Sato

Journal of Applied Physics   99 ( 5 ) 053505-1 - 053505-6   2006.03  [Refereed]

Research paper (journal)   Domestic Co-author