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Publications & Conferences

Papers

2024

  • "Deep learning for three-dimensional segmentation of electron microscopy images of complex ceramic materials,"
    Y. Hirabayashi, H. Iga, H. Ogawa, S. Tokuta, Y. Shimada, A. Yamamoto:
    npj Computational Materials, 10 46 1-10 (2024).
  • "Superconducting (Ba,K)Fe2As2 Epitaxial Films on Single and Bicrystal SrTiO3 Substrates,"
    D. Qin, Z. Guo, C. Tarantini, S. Hata, M. Naito, and A. Yamamoto:
    Applied Physics Letters, 125 182601 1-6 (2024).
  • "High-Fidelity Phase-Field Simulation of Solid-State Sintering Enabled by Bayesian Data Assimilation Using In Situ Electron Tomography Data,"
    A. Ishii, A. Yamanaka, M. Yoshinaga, S. Sato, M. Ikeuchi, H. Saito, S. Hata, and A. Yamamoto:
    Acta Materialia, 278, 120251 1-11 (2024).
  • "Super-strength permanent magnets with iron-based superconductors by data- & researcher-driven process design,"
    A. Yamamoto, S. Tokuta, A. Ishii, A. Yamanaka, Y. Shimada & M. D. Ainslie:
    NPG Asia Materials, 16 29 1-12 (2024).
  • "Planar defects and strain distributions in polycrystalline BaFe2As2 superconductors synthesized by mechanochemical methods,"
    Z. Guo, K. Muraoka, H. Gao, Y. Shimada, T. Harada, S. Tokuta, Y. Hasegawa, A. Yamamoto, S. Hata:
    Acta Materialia, 266, 119648 1-9 (2024).
  • "Structural analysis and transport properties of [010]-tilt grain boundaries in Fe(Se,Te),"
    K. Iida, Y. Yamauchi, T. Hatano, K. Walther, B. Holzapfel, J. Hänisch, Z. Guo, H. Gao, H. Shi, S. Tokuta, S. Hata, A. Yamamoto and H. Ikuta:
    Science and Technology of Advanced Materials, 25 2384829 1-9 (2024).
  • "High tolerance of the superconducting current to the large grain boundary angles in potassium doped BaFe2As2,"
    T. Hatano, D. Qin, K. Iida, H. Gao, Z. Guo, H. Saitoh, S. Hata, Y. Shimada, M. Naito, A. Yamamoto:
    NPG Asia Materials, 16 41 1-10 (2024).
  • "データ科学を活用した超電導材料新規創製プロセス開発の可能性,"
    嶋田雄介、石井秋光、尾崎壽紀、山本明保:
    電気学会論文誌A（基礎・材料・共通部門誌）, 144, No. 9, 360-365 (2024)
  • "金属・セラミックス技術分野のインフォマティクス応用の最前線,"
    山本明保:
    電気学会論文誌A（基礎・材料・共通部門誌）, 144, No. 1, 19-20 (2024)

2023

  • "Development of a highly stable nickel-foam-based boron monosulfide–graphene electrocatalyst with a high current density for the oxygen evolution reaction,"
    L. Li, C. Jiang, N. Watanabe, A. Yamamoto, T. Fujita, M. Miyakawa, T. Taniguchi, H. Hosono and T. Kondo:
    Science and Technology of Advanced Materials, 24, 2277681 1-8 (2023).
  • "Rhombohedral boron monosulfide as a metal free photocatalyst,"
    K. Miyazaki, A. Yamaguchi, H. Kusaka, N. Watanabe, A. Yamamoto, M. Miyakawa, T. Taniguchi, T. Kondo, and M. Miyauchi:
    Scientific Reports, 13, 19540 1-10 (2023).
  • "Application of Bayesian Optimization to the Synthesis Process of BaFe2(As,P)2 Polycrystalline Bulk Superconducting Materials,"
    A. Ishii, S. Kikuchi, A. Yamanaka, A. Yamamoto:
    Journal of Alloys and Compounds, 966, 171613 1-7 (2023).
  • "Boron monosulfide as an electrocatalyst for the oxygen evolution reaction,"
    L. Li, S. Hagiwara, C. Jiang, H. Kusaka, N. Watanabe, T. Fujita, A. Yamamoto, M. Miyakawa, T. Taniguchi, H. Hosono, F. Kuroda, M. Otani, and T. Kondo:
    Chemical Engineering Journal, 471, 144489 1-9 (2023).
  • "Recent progress on epitaxial growth of Fe-based superconducting thin films,"
    K. Iida, J. Hanisch, S. Hata, and A. Yamamoto:
    Superconductor Science & Technology, 36, 063001 1-15 (2023).
  • "DMC-TPE: Tree-Structured Parzen Estimator-Based Efficient Data Assimilation Method for Phase-Field Simulation of Solid-State Sintering,"
    A. Ishii, A. Yamamoto, A. Yamanaka:
    STAM Methods, 3, 2239133 1-17 (2023).
  • "Rhombohedral boron monosulfide as a p-type semiconductor,"
    N. Watanabe, K. Miyazaki, M. Toyoda, K. Takeyasu, N. Tsujii, H. Kusaka, A. Yamamoto, S. Saito, M. Miyakawa, T. Taniguchi, T. Aizawa, T. Mori, M. Miyauchi, and T. Kondo:
    Molecules, 28, 1896 1-9 (2023).
  • "Phase-field modeling of solid-state sintering with interfacial anisotropy,"
    A. Ishii, K. Kondo, A. Yamamoto, A. Yamanaka:
    Materials Today Communications, 35, 106061 1-11 (2023).
  • "A comparative study of experimental and simulational trapped magnetic field of MgB2 bulks by the Magnesium Vapor Transport process,"
    N. Ikeda, M. Ainslie, R. Tanaka, A. Yamamoto:
    IEEE Transactions on Applied Superconductivity, 33, 6800505 1-5 (2023).

2022

  • "Enhanced critical current density in K-doped Ba122 polycrystalline bulk superconductors via fast densification,"
    S. Tokuta, Y. Hasegawa, Y. Shimada, A. Yamamoto:
    iScience, 25, 103992 1-11 (2022).
  • "BOXVIA: Bayesian optimization executable and visualizable application,"
    A. Ishii, R. Kamijyo, A. Yamanaka, and A. Yamamoto:
    SoftwareX, 18, 101019 1-8 (2022).
  • "Recent advances and challenges in MgB2 superconducting bulks,"
    A. Yamamoto:
    Journal of the Cryogenic Society of Japan, 57, 3-8 (2022).
  • "Efficient estimation of material parameters using 4DVar-BO: Application to phase field simulation of solid state sintering,"
    A. Ishii, A. Yamanaka, E. Miyoshi, and A. Yamamoto:
    Materials Today Communications, 30, 103089 1-13 (2022).
  • "Thickness Dependence of Trapped Magnetic Fields in Bulk MgB2 Superconductors,"
    M. Ainslie, A. Yamamoto:
    IEEE Transactions on Applied Superconductivity, 32, 6800504 1-4 (2022).
  • "3D microstructure and critical current properties of ultra-fine-grain Ba(Fe,Co)2As2 bulk superconductors,"
    Y. Shimada, S. Tokuta, A. Yamanaka, A. Yamamoto, T. J. Konno:
    Journal of Alloys and Compounds, 923, 166358 1-7 (2022).
  • "K-doped Ba122 epitaxial thin film on MgO substrate by buffer engineering,"
    D. Qin, K. Iida, Z. Guo, C. Wang, H. Saito, S. Hata, M. Naito, A. Yamamoto:
    Superconductor Science & Technology - Letters, 35, 09LT01 1-6 (2022).
  • "MgB2 thin films fabricated by pulsed-laser deposition using Nd–YAG laser in an in-situ two-step process,"
    T. Ozaki, S. Kikukawa, R. Tanaka, A. Yamamoto, A. Tsuruta, Y. Tsuchiya:
    Condensed Matter, 7, 48 1-8 (2022).

2021

  • "Approaching the ultimate superconducting properties of (Ba,K)Fe2As2 by naturally formed low-angle grain boundary networks,"
    K. Iida, D. Qin, C. Tarantini, T. Hatano, H. Saito, C. Wang, Z. Guo, H. Gao, H. Saito, S. Hata, M. Naito, A. Yamamoto:
    NPG Asia Mat., 13, 68 1-9 (2021).
  • "Crystalline boron monosulfide nanosheets with tunable bandgaps,"
    H. Kusaka, R. Ishibiki, M. Toyoda, T. Fujita, T. Tokunaga, A. Yamamoto, M. Miyakawa, K. Matsushita, K. Miyazaki, L. Li, S. L. Shinde, T. Sakurai, E. Nishibori, T. Masuda, K. Horiba, K. Watanabe, S, Saito, M. Miyauchi, T. Taniguchi, H. Hosono, and T. Kondo:
    Journal of Materials Chemistry A, 9, 24631-24640 (2021).
  • "Estimation of solid-state sintering and material parameters using phase-field modeling and ensemble four-dimensional variational method,"
    A. Ishii, A. Yamanaka, Y. Okada, A. Yamamoto:
    Modelling Simul. Mater. Sci. Eng., 29, 065012 1-27 (2021).
  • "Thermal response of the iron-based Ba122 superconductor to in situ and ex situ processes,"
    S. Tokuta, A. Yamamoto:
    Superconductor Science & Technology, 34, 034004 1-7 (2021).
  • "Realization of epitaxial thin films of the superconductor K-doped BaFe2As2,"
    D. Qin, K. Iida, T. Hatano, H. Saito, Y. Ma, C. Wang, S. Hata, M. Naito, A. Yamamoto:
    Physical Review Materials , 5, 014801 1-6 (2021).

2020

  • "From a fascinating phenomenon towards an enabling technology: a breakthrough for higher and more reliable field trapping in HTS bulks,"
    A. Yamamoto:
    Superconductor Science & Technology (Viewpoint), 33, 120501 1-3 (2020).
  • "Evolution of inter-granular microstructure and critical current properties of polycrystalline Co-doped BaFe2As2 through high-energy milling,"
    S. Tokuta, Y. Shimada, A. Yamamoto:
    Superconductor Science & Technology, 33, 094010 1-8 (2020).
  • "Preface to the special issue ‘Focus on 10 Years of Iron-Based Superconductors’,"
    I. Pallecchi, C. Tarantini, J. Hänisch, and A. Yamamoto:
    Superconductor Science & Technology, 33, 090301 1-7 (2020).
  • "Quantitative analysis of meandering and dimensional crossover of conduction path in 3D disordered media by percolation modeling,"
    T. Obara, and A. Yamamoto:
    Superconductor Science & Technology, 33, 074004 1-7 (2020).
  • "Trapped Magnetic Field and Levitation Force Properties of Multi-Seeded YBCO Superconductors with Different Seed Distance,"
    B. Savaskan, S. Güner, A. Yamamoto, K. Ozturk, S. Celik:
    Journal of Alloys and Compounds, 829, 154400 1-8 (2020).
  • "Grain boundary characteristics of Fe-based superconductors,"
    K. Iida, J. Hänisch, and A. Yamamoto:
    Superconductor Science & Technology (Topical Review), 33, 043001 1-13 (2020).
  • "高温超電導バルクの材料研究開発における新展開,"
    山本明保、井田徹哉、Mark AINSLIE、坂井直道、下山淳一、内藤智之、成木紳也、和泉充:
    電気学会論文誌B（電力・エネルギー部門誌）, 140, No. 3, 1-7 (2020)
    （2020年3月号「未来社会創造に向けた超電導バルク材の挑戦」特集号）

2019

  • "Enhanced upper critical field in Co-doped Ba122 superconductors by lattice defect tuning,"
    S. Tokuta, and A. Yamamoto:
    APL Materials, 7, 111107 1-6 (2019).
  • "Development of Highly Pure Polycrystalline Superconducting MgB2 Bulks by Mg Vapor Transport (MVT) Method,"
    Y. Sanogawa, and A. Yamamoto:
    Journal of the Japan Institute of Metals, 83, 341-345 (2019).
  • "Formation of defects and their influence on inter- and intra-granular current in sintered polycrystalline 122 phase Fe-based superconductors,"
    Y. Shimada, A. Yamamoto, Y. Hayashi, K. Kishio, J. Shimoyama, S. Hata, T. J. Konno:
    Superconductor Science & Technology, 32, 084003 1-9 (2019).
  • "Semi-metallicity of free-standing hydrogenated monolayer boron from MgB2,"
    I. Tateishi, N. T. Cuong, C.A.S. Moura, M. Cameau, R. Ishibiki, A. Fujino, S. Okada, A. Yamamoto, M. Araki, S. Ito, S. Yamamoto, M. Niibe, T. Tokushima, D.E. Weibel, T. Kondo, M. Ogata, and I. Matsuda:
    Physical Review Materials, 3, 3, 024004 1-8 (2019).

2018

  • "High Trapped Fields in C-doped MgB2 Bulk Superconductors Fabricated by Infiltration and Growth,"
    M. Kodama, K. Tanaka, K. Okamoto, A. Yamamoto, J. Shimoyama:
    Materials Research Express, 6, 026003 1-11 (2018).
  • "High Trapped Fields in C-doped MgB2 Bulk Superconductors Fabricated by Infiltration and Growth,"
    A. G. Bhagurkar, A. Yamamoto, L. Wang, M. Xia, A. R. Dennis, J. H. Durrell, T. A. Aljohani, N. Hari Babu, and D. A. Cardwell:
    Scientific Reports, 8, 13320 1-12 (2018).
  • "Recent advances in iron-based superconductors toward applications,"
    H. Hosono, A. Yamamoto, H. Hiramatsu, Y. Ma:
    Materials Today, 21, 278-302 (2018).

2017

  • "Development of iron-based superconducting bulk magnet,"
    A. Yamamoto, J. Weiss, M. Ainslie, A. Polyanskii, D. Larbalestier and E. Hellstrom:
    Journal of the Cryogenic Society of Japan 52, 397-404 (2017).
  • "Numerical modelling of iron-pnictide bulk superconductor magnetisation,"
    M. Ainslie, A. Yamamoto, H. Fujishiro, J. Weiss and E. Hellstrom:
    Superconductor Science & Technology 30, 105009 1-7 (2017).
  • “Selective mass enhancement close to the quantum critical point in BaFe2(As1-xPx)2”
    V. Grinenko, K. Iida, F. Kurth, D. V. Efremov, S. L. Drechsler, I. Cherniavskii, I. Morozov, J. Hanisch, T. Forster, C. Tarantini, J. Jaroszynski, B. Maiorov, M. Jaime, A. Yamamoto, I. Nakamura, R. Fujimoto, T. Hatano, H. Ikuta, R. Huhne:
    Scientific Reports 7, 4589 (2017).
  • “Microstructural evolution in Infiltration-Growth processed MgB2 bulk superconductors,”
    A. G. Bhagurkar, A. Yamamoto, A. R. Dennis, J. H. Durrell, T. A. Aljohani, N. Hari Babu, and D. A. Cardwell:
    Journal of the American Ceramic Society 100, 2451-2460 (2017).
  • “Formation mechanism of boron-based nanosheet through the reaction of MgB2 with water,”
    H. Nishino, T. Fujita, A. Yamamoto, T. Fujimori, A. Fujino, S. Ito, J. Nakamura, H. Hosono, and T. Kondo:
    Journal of Physical Chemistry C 121, 10587-10593 (2017).
  • “High-performance dense MgB2 superconducting wire prepared by mechanical milling,”
    M. Kodama, T. Suzuki, H. Tanaka, K. Okishiro, K. Okamoto, G. Nishijima, A. Matsumoto, A. Yamamoto, J. Shimoyama, and K. Kishio :
    Superconductor Science & Technology 30, 044006 1-7 (2017).

2016

  • “鉄系超伝導体のマルチスケール結晶粒構造観察,”
    嶋田雄介、今野豊彦、山本明保、波多聰 :
    まてりあ 55, 600 (2016).
  • “Electromagnetic properties and microstructures of in situ MgB2 wires made from three types of boron,”
    M. Kodama, H. Kotaki, H. Yamamoto, T. Iwane, K. Tanaka, H. Tanaka, K. Okishiro, K. Okamoto, G. Nishijima, A. Matsumoto, H. Kumakura, A. Yamamoto, J. Shimoyama, and K. Kishio:
    Superconductor Science & Technology 29, 105016 1-11 (2016).
  • “A defect detection method for MgB2 superconducting and iron-based Ba(Fe,Co)2As2 wires,”
    D. J. Gajda, A. J. Morawski, A. J. Zaleski, A. Yamamoto, and T. Cetner:
    Applied Physics Letters 108, 152601 1-4 (2016).
  • “Development of polycrystalline bulk MgB2 superconducting magnet by hot-pressing,”
    Y. Yamada, H. Ohuchi, A. Yamamoto, and K. Kishio:
    Journal of the Japan Institute of Metals 80, 457-461 (2016).
  • “A trapped magnetic field of 3 T in homogeneous, bulk MgB2 superconductors fabricated by a modified precursor infiltration and growth process,”
    A. G. Bhagurkar, A. Yamamoto, L. Anguilano, A. Dennis, N. Hari Babu, and D. A. Cardwell:
    Superconductor Science & Technology 29, 035008 1-8 (2016).
  • “Small grains: A key to high-field applications of granular Ba-122 superconductors?,”
    J. Hecher, T. Baumgartner, J. D. Weiss, C. Tarantini, A. Yamamoto, J. Jiang, E. E. Hellstrom, D. C. Larbalestier, and M. Eisterer: Superconductor Science & Technology 29, 025004 1-10 (2016).
  • “Microstructural connectivity in sintered ex situ MgB2 bulk superconductors,”
    Y. Shimada, S. Hata, K. Ikeda, H. Nakashima, S. Matsumura, H. Tanaka, A. Yamamoto, J. Shimoyama, and K. Kishio:
    Journal of Alloys and Compounds 656, 172-180 (2016).

2015

  • “Demonstration of an iron-pnictide bulk superconducting magnet capable of trapping over 1 T,”
    J. D. Weiss, A. Yamamoto, A. A. Polyanskii, R. B. Richardson, D. C. Larbalestier, and E. E. Hellstrom:
    Superconductor Science & Technology – Fast Track Communication 28, 112001 1-6 (2015).
  • “Synthesis of highly connected bulk MgB2 by infiltration and growth,”
    A. G. Bhagurkar, A. Yamamoto, N. Hari Babu, J. H. Durrell, A. R. Dennis and D. A. Cardwell:
    Superconductor Science & Technology 28, 015012 1-6 (2015).
  • “Numerical modelling and comparison of MgB2 bulks fabricated by HIP and infiltration growth magnetized by field cooling,”
    J. Zou, M. D. Ainslie, H. Fujishiro, A. G. Bhagurkar, T. Naito, N. Hari Babu, J. F. Fagnard, P. Vanderbemden, and A. Yamamoto:
    Superconductor Science & Technology 28, 075009 1-9 (2015).
  • “Microstructural characteristics of ball-milled, self-sintered ex situ MgB2 bulks,”
    Y. Shimada, S. Hata, K. Ikeda, H. Nakashima, S. Matsumura, H. Tanaka, A. Yamamoto, J. Shimoyama, and K. Kishio:
    IEEE Transactions on Applied Superconductivity 25, 6801105 1-5 (2015).
  • “Enhanced trapped field in MgB2 bulk magnets by tuning grain boundary pinning through milling,”
    S. Sugino, A. Yamamoto, J. Shimoyama, and K. Kishio:
    Superconductor Science & Technology 28, 055016 1-7 (2015).

Book chapter

  • “Processing of low Tc conductors: the compound MgB2,”
    Akiyasu Yamamoto and René Flükiger:
    HANDBOOK OF SUPERCONDUCTING MATERIALS Second Edition, 第E3.3.6章, 1-26, David Cardwell and David Larbalestier 編, Taylor & Francis Books, Inc (in-press).
  • “MgB2,”
    山本明保:
    超伝導磁束状態の物理, 第4.2章, 323-330, 門脇和男 編, 裳華房(2017).
  • “Chemically and Mechanically Engineered Flux Pinning for Enhanced Electromagnetic Properties of MgB2,”
    S. K. Chen, M. Maeda, A. Yamamoto, S. X. Dou:
    Vortices and Nanostructured Superconductors, 第3章, 65-108, Ed. Adrian Crisan, Springer (2017).
  • “Bulk MgB2 Permanent Magnet,”
    A. Yamamoto, and K. Kishio:
    MgB2 Superconducting Wires - Basics and Applications, Chapter 6b., 537-548, Ed. Rene Flukiger, World Scientific Publishing Company (2016).

Conferences

2020

  • "Recent progress on the development of K-doped Ba122 bulk superconductors " (招待講演)
    Akiyasu Yamamoto1,2,8, Shinnosuke Tokuta1,8, Yuta Hasegawa1, Rikuta Fujii1, Yuki Okada1, Yusuke Shimada3,8, Hikaru Saito4,8, Satoshi Hata4,5,8, Akimitsu Ishii6,8, Akinori Yamanaka6,8, Kazumasa Iida7,8
    "Synthesis of K-doped Ba122 polycrystalline bulks with high critical current density"
    S. Tokuta, Y. Hasegawa, R. Fujii, Y. Shimada, S. Hata, and A. Yamamoto
    "Critical current properties of in situ grown (Ba,K)Fe2As2 epitaxial thin films"
    Dongyi Qin1, Kazumasa Iida2, 5, Chriara Tarantini3, Wang Chao4, Hikaru Saito4, 5, Satoshi Hata4, 5, Michio Naito1, 5, Akiyasu Yamamoto
    33rd International Symposium on Superconductivity
    ???, Dec. 1-3, 2020
  • "Bayesian engineered high critical current density in K doped Ba122 polycrystalline materials"
    A.Yamamoto, S.Tokuta, R. Fujii, Y.Okada, Y.Shimada, S.Hata, K.Iida, A. Yamanaka
    "Highly dense K-doped Ba122 polycrystalline bulks prepared by Spark Plasma Sintering"
    S. Tokuta1,4, R. Fujii1, Y. Shimada2,4, S. Hata3,4, A. Yamamoto1,4
    "In-situ growth of (Ba,K)Fe2As2 epitaxial thin films by molecular beam epitaxy"
    D. Qin, K. Iida, Y. Ma, H. Saito, S. Hata, M. Naito, A. Yamamoto
    "Influence of synthesis condition on grain-structure of Ba-122 polycrystalline bulks"
    Y. Shimada, S. Tokuta, Y. Okada, A. Yamanaka, A. Yamamoto, T. J. Konno
    Applied Superconductivity Conference 2020
    Online (originally Tampa Convention Center, Tampa, USA), Oct. 25-Nov. 7, 2020
  • "Recent progress in the development of Ba122 polycrystalline bulk materials"（招待講演）
    A.Yamamoto, S.Tokuta, T.Obara, A.Yamanaka, Y.Shimada, S.Hata, K.Iida
    Iron-based Superconductors: advances towards applications
    Santa Margherita Ligure, Genoa, Italy, Feb. 12-14, 2020
  • "Modeling the effects of microstructural defects on the current transport in polycrystalline bulk superconductors"
    T. Obara, A. Yamamoto
    "Understanding routes for controlling inter- and intra-granular structure of polycrystalline Ba122 superconducting materials"（招待講演）
    A.Yamamoto, S.Tokuta, T.Obara, Y.Okada, A.Ishii, A.Yamanaka, Y.Shimada, S.Hata, K.Iida
    10th ACASC/2nd Asian ICMC/CSSJ Joint Conference
    Okinawa Convention Center, Okinawa, Japan, Jan. 6-9, 2020

2019

  • "Large-scale phase-field simulation of solid-state sintering in polycrystalline superconducting material using parallel computing"
    A. Ishii, A. Yamanaka, Y. Okada, A. Yamamoto
    Asian Pacific Congress on Computational Mechanics
    Taipei International Convention Center, Taipei, Taiwan, Dec. 18-21, 2019
  • "Intra- and inter-granular superconducting properties and microstructure of BaFe2As2 polycrystalline bulks prepared by high energy milling"
    S. Tokuta, A. Yamamoto, Y. Shimada, S. Hata
    "3D Phase-Field Modeling of Grain-Boundary Formation during Solid-State Sintering: The Dependence of Diffusion Mechanisms"
    Y. Okada, A. Yamamoto, A. Ishii, A. Yamanaka
    "Modeling the normal-state current transport in iron-based superconducting polycrystalline materials"
    T. Obara, A. Yamamoto
    "Material Parameter Estimation for Phase-field Simulation of Solid-state Sintering using Data Assimilation"
    A. Yamanaka, A. Ishii, Y. Okada, Y. Shimada, A. Yamamoto
    "Carbon doping of hydrogen boride sheet reduces H2 release temperature"
    T. Kondo, R. Ishibiki, T. Goto, T. Fujita, Y. Fujimoto, A. Yamamoto, S. Saito, and H. Hosono
    Materials Research Meeting 2019
    PACIFICO YOKOHAMA, Yokohama, Japan, Dec. 10-14, 2019
  • "A comparative study of experiments and simulations on grain-boundary formation of polycrystalline Ba122 phase iron-based superconductors"
    Yuki Okada, Shinnosuke Tokuta, Yusuke Shimada, Akimitsu Ishii, Akinori Yamanaka, Akiyasu Yamamoto
    "Modeling transport current in polycrystalline superconducting materials"
    Akiyasu Yamamoto, Takuya Obara
    The 11th International Conference on the Science and Technology for Advanced Ceramics
    MRS2019 Fall Meeting, Boston, America, Dec. 1-6, 2019
  • "Development of high-performance MgB2 wires fabricated from mechanically milled powder"
    Motomune Kodama, Hiroshi Kotaki, Takaaki Suzuki, Hideki Tanaka, Ryuya Ando, Takeshi Nakayam, Gen Nishijima, Akiyoshi Matsumoto, Akiyasu Yamamoto, Jun-ichi Shimoyama
    "The effects of high energy milling on intra- and inter-granular superconducting properties of 122 phase iron-based superconducting polycrystalline bulks"
    S. Tokuta, A. Yamamoto, Y. Shimada, S. Hata
    "Synthesis of Ba122 thick films by vapour diffusion method"
    T. Uemura, A. Yamamoto
    "Development of MVT-MgB2 bulks assisted by combined defect detection & simulation"
    A. Yamamoto, Y. Sanogawa, K. Iso, T. Obara, M. Saito
    14th European Conference on Applied Superconductivity
    Scottish Event Campus, Glasgow, UK, Sep. 1-5, 2019
  • "Percolation modeling of current transport in polycrystalline bulk iron-based superconductors"
    T. Obara, A. Yamamoto
    "Simple and non-destructive technique to detect internal inhomogeneity of superconducting bulks"
    K. Iso, T. Obara, Y. Sanogawa, A. Yamamoto
    "Influences of starting MgB2 powder on the sintering behavior of ex situ MgB2 bulks"
    K. Nakanishi, A. Yamamoto
    "Dense MgB2 bulks prepared by Mg vapour transport (MVT) process and simple non-destructive technique for detecting internal defects"
    A. Yamamoto, Y. Sanogawa, K. Iso, T. Obara, M. Saito
    "Numerical modelling and comparison of MgB2 bulks fabricated by HIP and infiltration growth"
    M. D. Ainslie1,*, J. Zou1, H. Fujishiro2, A. G. Bhagurkar3, T. Naito2, N. Hari Babu3, J-F. Fagnard4, P. Vanderbemden4, A. Yamamoto5
    11th International Workshop on Processing and Applications of Superconducting Bulk Materials
    Novotel Praha Wenceslas Square, Prague ,Czech Republic, Arg. 29, 2019
  • "Investigation of thermal behavior and phase formation of BaFe2As2 and Ba(Fe,Co)2As2 by TG-DSC analysis"
    S. Tokuta, A. Yamamoto
    "Percolation modeling of current transport in polycrystalline bulk iron-based superconductors"
    T. Obara, A. Yamamoto
    "3D Phase-field Modeling of Grain-Boundary Formation during Solid-State Sintering"
    Y. Okada, A. Yamamoto, A. Ishii, A. Yamanaka
    The 11th International Conference on the Science and Technology for Advanced Ceramics
    Tsukuba International Congress Center (EPOCHAL), Tsukuba, Japan, Jul. 9-11, 2019

2018

  • "Recent topics of iron-pnictide bulk superconductors"（招待講演）
    A. Yamamoto, S. Tokuta, M. D. Ainslie, J. D. Weiss, A. A. Polyanskii, E. E. Hellstrom, D. C. Larbalestier
    "Effects of Lattice Defects on the Superconducting Properties of Ba122 Polycrystalline Materials Prepared by High Energy Ball-Milling"
    S. Tokuta, A. Yamamoto
    "Synthesis and trapped field properties of dense MgB2 bulks by Magnesium Vapor Transportation (MVT) method" Y. Sanogawa, A. Yamamoto
    31th International Symposium on Superconductivity
    Epochal Tsukuba, Tsukuba, Japan, Dec. 12-14, 2018
  • "Understanding the route for high intergranular current in 122 phase iron-based superconducting polycrystalline bulks through high energy milling"
    S. Tokuta, A. Yamamoto
    "Fabrication of dense MgB2 bulks by Magnesium Vapor Transportation (MVT) method"
    Y. Sanogawa, A. Yamamoto
    "Interplay of grain connectivity and pinning properties in MgB2 and Fe-based superconductors synthesized under high pressure: dominant factors leading to increased critical current density"
    Tomasz Cetner, Andrzej Morawski, Akiyasu Yamamoto, Wolfgang Hässler, Daniel Gajda, Grzegorz Gajda, Matthew Rindfleisch, Mustafa Akdogan, Hakan Yetis, Ibrahim Belenli, Andrzej Zaleski, Ryszard Diduszko, Piotr Przyslupski
    "Exploring the potential of MgB2 superconducting bulk magnet"（招待講演）
    A. Yamamoto, Y. Sanogawa, K. Ishikawa, M. Michishita, N. Shimazaki
    Applied Superconductivity Conference 2018
    Washington State Convention Center, Seattle, USA, Oct. 29-Nov. 1, 2018
  • "Iron-based superconductors for bulk magnet applications"（招待講演）
    A. Yamamoto, S. Tokuta, J. D. Weiss, M. D. Ainslie, A. A. Polyanskii, D. C. Larbalestier, and E. E. Hellstrom
    International Workshop on Recent Progress in Superconductivity 2018
    Yongpyong Resort, Pyeongchang, Korea, Jul. 10, 2018
  • "Magnet application of Iron-based superconductors"（招待講演）
    A. Yamamoto, J. D. Weiss, M. D. Ainslie, A. A. Polyanskii, D. C. Larbalestier, and E. E. Hellstrom
    14th International Conference on Modern Materials and Technologies & 8th Forum on New Materials
    Centro Congressi Hotel Quattrotorri at Best Western Hotel Quattrotorri Perugia, Perugia, Italy, Jun. 11, 2018
  • "New Candidates for Superconducting Bulk Applications: MgB2 and Fe-based Superconductors"（基調講演）
    A. Yamamoto
    6th International Conference on Superconductivity and Magnetism
    Premier Palace Hotel, Beldibi, Antalya ,Turkey, Apr. 30 , 2018

2017

  • "Novel strong magnet made with iron-based high temperature superconductor"
    A. Yamamoto
    Japanese-American-German Frontiers of Science Symposium
    Steigenberger Hotel Bad Neuenahr, Bad Neuenahr, Germany, Sep. 22 , 2017
  • “Achievements of high pressure MgB₂ synthesis: can in situ samples　reach mass density and grain connectivity of Mg diffusion samples?”
    Tomasz Cetner, Andrzej Morawski, Akiyasu Yamamoto, Wolfgang Häßler, Daniel Gajda, Grzegorz Gajda, Matt Rindfleisch, Andrzej Zaleski, Tomasz Czujko, Piotr Przysłupski
    “Optimization of high isostatic pressure annealing processes for　fabrication of MgB₂ and Ba(Fe,Co)₂As₂ superconducting wires with high critical current density”
    S. Tokuta, A. Yamamoto
    "High Trapped Fields in C-doped Mg(B1-xCx)2 Bulk Superconductors Fabricated by Infiltration and Growth"
    Ashutosh G. Bhagurkar, Akiyasu Yamamoto, Anthony R. Dennis, John H. Durrell, N Hari Babu, David A. Cardwellbr
    "The key microstructural factors for high transport current in randomly oriented 122 polycrystalline materials"
    A. Yamamoto, Y. Shimada, S. Tokuta, Y. Hayashi, K. Kishio, J. Shimoyama ,S. Hata
    13th European Conference on Applied Superconductivity
    International Conference Centre of Geneva (CICG), Geneve, Switerland, Sep. 18, 2017
  • “Fabrication of large MgB2 bulks by Mg vapor transportation (MVT) method”
    A. Yamamoto, K. Kishio, H. Ohuchi, Y. Yamada
    “Intergranular current transport properties in polycrystalline 122 phase Fe-based superconductors synthesized through high energy milling”
    S. Tokuta, A. Yamamoto
    "Multiscale structural observation of randomly oriented 122 polycrystalline materials"
    A. Yamamoto, Y. Shimada, S. Tokuta, Y. Hayashi, K. Kishio, J. Shimoyama ,S. Hata
    IUMRS-ICAM2017
    Kyoto University, Kyoto, Japan, Aug. 30, 2017
  • "Development of 122 Phase Fe-Based Polycrystalline Bulk Superconductors by High Energy Milling Process"
    S. Tokuta, A. Yamamoto
    "Fabrication of Large MgB2 Bulks by Mg Vapor Transportation (MVT) Method"
    Y. Sanogawa, N. Shimazaki, A. Yamamoto
    The Tenth International Conference on the Science and Technology for Advanced Ceramics (STAC-10)
    Mielparque-Yokohama, Yokohama, Japan, Aug. 1, 2017
  • "Trapped field property of iron-pnictide bulk magnet"
    A. Yamamoto, J. D. Weiss, A. A. Polyanskii, R. B. Richardson, D. C. Larbalestier, and E. E. Hellstrom
    The Cryogenic Engineering Conference and the International Cryogenic Materials Conference 2017
    Monona Terrace, Madison, USA, Jul. 10, 2017

2016

  • “Enhanced trapped field and mechanical strength in dense bulk MgB2” (招待講演)
    A. Yamamoto, K. Kishio, H. Ohuchi, Y. Yamada
    “Mechanism for High Critical Current Density in MgB2 Wire Prepared by Mechanical Milling Technique”
    M. Kodama, H. Tanaka, K. Okamoto, A. Yamamoto, J. Shimoyama, K. Kishio
    1st Asian ICMC and CSSJ 50th Anniversary Conference
    Kanazawa Theatre, Kanazawa, Nov. 7-10, 2016
  • “Trapped field property of iron-pnictide bulk magnet”
    A. Yamamoto, J. D. Weiss, A. A. Polyanskii, R. B. Richardson, D. C. Larbalestier, and E. E. Hellstrom
    “Successful manufacturing of dense PIT MgB2 wires”
    M. Kodama, H. Kotaki, H. Yamamoto, S. Tanigawa, K. Nishi, H. Tanaka, K. Okishiro, K. Okamoto, G. Nishijima, A. Matsumoto, A. Yamamoto, J. Shimoyama, and K. Kishio
    Applied Superconductivity Conference 2016
    Colorado Convention Center, Denver, Sep. 4-9, 2016
  • “高磁場応用に向けたMgB2と 鉄系超伝導材料の基礎開発” (招待講演)
    山本明保
    低温工学・超電導学会 東北・北海道支部/第２回材料研究会 合同シンポジウム
    洞爺観光ホテル, 北海道, Aug. 2-3, 2016
  • “Controlling the formation of grain boundaries in ex-situ MgB2 bulks and wires” (招待講演)
    A. Yamamoto, Y. Shimada, S. Hata, J. Shimoyama, S. Mizutani, K. Kishio, M. Kodama and H. Tanaka
    “Experimental and theoretical investigation of the correlation between small grains and large transport currents in Ba122”
    J. Hecher, T. Baumgartner, J.D. Weiss, C. Tarantini, A. Yamamoto, J. Jiang, E.E. Hellstrom, D.C. Larbalestier and M. Eisterer
    5th International Conference on Superconductivity and Magnetism
    Liberty Hotels Lykia & Sentido Lykia Resorts Spa, Fethiye, Apr. 24-30, 2016

2015

  • “材料分野の国際研究開発動向” (依頼講演)
    山本明保
    第92回低温工学・超電導学会研究発表会
    姫路商工会議所, Dec. 3, 2015.
  • “Modeling intergranular current transport in Fe-based superconductors” (招待講演)
    A. Yamamoto, M. Eisterer
    14th International Union of Materials Research Societies - International Conference on Advanced Materials
    Jeju International Convention Center, Jeju, Oct. 27, 2015
  • “Overcoming the adverse effects of granularity on the critical current density in iron-based superconductors”
    HECHER Johannes, BAUMGARTNER Thomas, WEISS Jeremy, JIANG Jianyi, KAMETANI Fumitake, TARANTINI Chiara, HELLSTROM Eric, LARBALESTIER David, HAYASHI Yujiro, YAMAMOTO Akiyasu, SHIMOYAMA Jun-Ichi, EISTERER Michael
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 8, 2015.
  • “The high pressure treatment of MgB2 and the Iron-based superconductors; the way for their high Jc in practice application ”
    Andrzej Morawski, Tomasz Center, Ryszard Diduszko, Daniel Gajda, Grzegorz Gajda, Matt Rindfleisch, Andrzej Zaeski, Shahriar Hossain, Akiyasu Yamamoto, Tomasz Czujko, Emilia Zuchowska, Wolfgang Haessller, Piotr Przyslupski
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 8, 2015.
  • “Phosphorus doping level depenence of of microstructure and superconducting properties of BaFe2As2 polycrystalline bulks ”
    S. Tsujitake, A. Yamamoto, H. Ogino, J. Shimoyama, K. Kishio
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 8, 2015.
  • “Processing of homogeneous bulk MgB2 by an infiltration and growth process ”
    A. Bhagurkar, A. Yamamoto, N. H. Babu, A. Dennis, J. Durrell, D. Cardwell
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 8, 2015.
  • “Controlling the formation of grain boundaries in ex-situ MgB2 bulks and wires”
    A. Yamamoto, S. Mizutani, J. Shimoyama, K. Kishio, Y. Shimada, S. Hata, S. Matsumura, M. Kodama, H. Tanaka
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 8, 2015.
  • “Development of MgB2 Superconducting Bulk Permanent Magnet” (招待講演)
    A. Yamamoto, S. Sugino, K. Kishio, A. Ishihara, T. Akasaka, M. Tomita
    12th European Conference on Applied Superconductivity
    Lyon convention center, Lyon, Sep. 7, 2015.
  • “Enhanced trapped field in MgB2 bulk magnets by tuning grain boundary pinning” (招待講演)
    A. Yamamoto, S. Sugino, K. Kishio, A. Ishihara, T. Akasaka, M. Tomita
    The 9th International Workshop on Processing and Applications of Superconducting (RE)BCO Large Grain Materials
    University of Liege, Liege, Sep. 3, 2015.
  • “How can we control formation of GBs towards well connected, high field MgB2?” (招待講演)
    A. Yamamoto
    The International Committee for Future Accelerators Mini-workshop on High Field Magnets for Super proton proton Colliders
    Shanghai Jiao Tong University, Shanghai, Jun. 16, 2015.
  • “Development of MgB2 Superconducting Bulk Permanent Magnet” (招待講演)
    A. Yamamoto, S. Sugino, J. Shimoyama, K. Kishio, A. Ishihara, T. Akasaka, M. Tomita
    2015 MRS Spring Meeting & Exhibit
    Marriott Marquis, San Francisco, Apr. 7, 2015.