研究者詳細 - 神原　陽一

研究発表 - 神原　陽一

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Tc of a Copper-based high-Tc superconductor after heat treatments under hydrogen atmosphere

H. Namita, H. Sato, M. Matoba, S. Iwasaki, M. Fujioka, Y. Hara, T. Harada, M. Miura, and Y. Kamihara

International Conference of Asian Union of Magnetics Societies (IcAUMS) 2025,

2025年04月

口頭発表（一般）

Synthesis of the iron-based superconductor Sr2Mg0.3Ti0.7FeAsO3-delta

Y. Ueno, N. Azuma, Y. Kamihara, and M. Matoba

International Conference of Asian Union of Magnetics Societies (IcAUMS) 2025,

2025年04月

口頭発表（一般）

Thermoelectric properties of Rb(Cd, Zn)4As3

Keigo ONO, Yosuke GOTO, Yoichi KAMIHARA, Chul-ho LEE

Joint March Meeting and April Meeting: Global Physics Summit 2025 （Anaheim Convention Center, CA, USA） ,

2025年03月

口頭発表（一般）

"いわゆる"ジントル相化合物 (特定の結晶相を示す言葉では無く、結晶中に共有結合性の分子層と見なせる「局所構造」が観察できる多元系化合物群を表す俗語)は、熱電変換材料として期待されている。
その一種である122ジントル相化合物 (AM2X2, A: アルカリ金属/アルカリ土類, M: 遷移金属, X: ニクトゲン)は、高い機能性を示す。我々は、122ジントル層の類似構造である143-ジントル相化合物RbZn4As3の固溶体を作製し、
その輸送現象を報告する。ZnサイトへのCdの固溶により格子熱伝導率は低下した。

Microstructure Analysis of Nominal SmFeAsO0.77H0.12 using Magneto-optical Imaging Method

Hideo Namita, Tomoki Suemura, Ryosuke Sakagami, Tsuyoshi Tamegai, and Yoichi Kamihara

Iron-based Superconductors: Advances towards applications 2025 (IBS2app 2025),

2025年02月

ポスター発表

Evaluation of the catalytic abilities of oxygen evolution reaction (OER) of Co doped YBa2Cu3O7-delta (YBCO)

Rei Kuramochi, Taisuke Kaizuka, Masanori Matoba, and Yoichi Kamihara

Iron-based Superconductors: Advances towards applications 2025 (IBS2app 2025),

2025年02月

ポスター発表

Nominal SmFeAsO0.77H0.12の磁気光学イメージング

浪田秀郎, 末村智紀, 坂上良介, 為ケ井強, 神原陽一

第48回日本磁気学会学術講演会,

2024年09月

口頭発表（一般）

鉄系高温超伝導体Sr2Mg0.3Ti0.7FeAsO3-δの多結晶合成

上野友貴，東　伸彦，神原陽一，的場正憲

第48回日本磁気学会学術講演会,

2024年09月

口頭発表（一般）

Synthesis Co doped YBa2Cu3O7-delta (YBCO) and evaluation of catalytic ability in oxygen evolution reaction (OER) of YBCO

R. Kuramochi, T. Kaizuka, M. Matoba, and Y. Kamihara

The 5 th international symposium on advanced magnetic materials and applications (ISAMMA2024) （Quang Binh） ,

2024年08月

ポスター発表

The Catalytic Activity of Co-doped YBa2Cu3O7-δ for Oxygen Evolution Reaction

H. Tahara, R. Kuramochi, M. Matoba, and Y. Kamihara

The 5 th international symposium on advanced magnetic materials and applications (ISAMMA2024) （Quang Binh） ,

2024年08月

ポスター発表

Review on Functional Mixed Anion Layered Compounds (MALC) and Computational Chemical Analysis on a Representative MALC, Sr2VFeAsO3-δ

Y. Kamihara

The 2024 TechConnect World Innovation （メリーランド州） ,

2024年06月

ポスター発表

Mixed anion layered compounds (MALCs), which contain several different anions in crystallographic sites, are novel functional materials. Indeed, high-Tc superconductors [1], high-efficient thermoelectric conversion materials [2], transparent semiconductor [3], and electrical catalyst for oxygen evolution reaction [4] have been found in MALCs. In the conference, we demonstrate a review on the MALCs and magnetic properties of a representative MALC, Sr2VFeAsO3-δ. Sr2VFeAsO3-δ is a mixed anion layered compound with a thick-blocking layer composed by a perovskite-related vanadium oxide layer. In 2019, an electric and magnetic phase diagram as a function of oxygen deficiency (δ) on superconducting Sr2VFeAsO3-δ was experimentally demonstrated. In this study, the magnetic stability of V and Fe in Sr2VFeAsO3-δ (δ = 0, 0.25, 0.50) was theoretically verified based on the density functional theory. Stable magnetic phases of the V are antiferromagnetic ordered phase between two ferromagnetic V magnetic layers (so-called A-AFM) for δ = 0. And the stable magnetic phases of V are ferrimagnetic ordered phase (Ferri.) for δ = 0.25, 0.50. Magnetic phases of Fe are a stripe-type antiferromagnetic ordered phase (s-AFM) in δ = 0, 0.25, 0.50, although the magnetic phases of the Fe with δ = 0.25 shows almost the same formation energy between s-AFM and paramagnetic (PM) ordered phases. Theoretical magnetic ordered phases are qualitatively consistent with the experimental electronic and magnetic phase diagrams for Sr2VFeAsO3-δ, although quantitative differences appear between measured for amounts of element specific magnetic moments and theoretical ones. I wiil talk on "Mixed anion compound iron-based superconducting wire and its manufacturing method" in the conference.[5] [1] Y. Kamihara, et al, J. Am. Chem. Soc. 130, 3296-3297 (2008). Iron-based layered superconductor La[O1-xFx]FeAs (x = 0.05-0.12) with Tc = 26 K [2] M. Ishizawa, et al, J. Appl. Phys. 123, 245104 (2018). [3] K. Ueda, et al, Phys. Rev. B 69, 155305_1-4 (2004). Single-atomic-layered quantum wells built in wide-gap semiconductors LnCuOCh (Ln=lanthanide, Ch=chalcogen). [4] S. Hirai, et al, J. Mater. Chem. A 6, 15102-15109 (2018). Oxygen vacancy-originated highly active electrocatalysts for the oxygen evolution reaction [5] Y. Tojo, S. Iwasaki, M. Matoba, and Y. Kamihara, Japanese Patent No. 6814007 (2020). Mixed anion compound iron-based superconducting wire and its manufacturing method (in Japanese)

Thermoelectric properties of a mixed anion layered compound, LaCuChO (Ch = S, Se) with copper defects

Yoichi Kamihara, Nobuhiko Azuma, Tastuhide Fujioka, Yuya Tanaka, Masanori Matoba

The 9th Korea-Japan International Symposium on Materials Science & Technology (KJMST2024) in GCIM2024,

2024年06月

口頭発表（一般）

Several mixed anion layered compounds (MALCs) exhibit relatively high figure of merit (ZT).[1,2] Experimental and theoretical researches expect a promising functionality for the MALCs as thermoelectric materials, [3,4] however detailed carrier-doping mechanism and relations between crystallographic defect and resistivity are still controversial for representative mixed anion layered compounds, polycrystalline LaCu(S, Se)O bulk.[5,6,7,8] In the symposia, we demonstrate thermoelectric properties of polycrystalline LaCu(S, Se)O with a little deficient in Cu site.
[1] L. D. Zhao et al., Appl. Phys. Lett. 97, 092118_1-3 (2010). Bi1−xSrxCuSeO oxyselenides as promising thermoelectric materials
[2] Y. Liu et al., J. Am. Chem. Soc. 133, 20112-20115 (2011). Remarkable enhancement in thermoelectric performance of BiCuSeO by Cu deficiencies
[3] For a review, W. Tang et al., Materials Today Physics 35, 101104_1-22 (2023). BiCuSeO based thermoelectric materials: Innovations and challenges
[4] For a review, A. R. Natarajan et al., Phys. Rev. Mater. 7, 025405 (2023). High thermoelectric performance of layered LaAgXO (X = Se, Te) from electrical and thermal transport calculations
[5] H. Hiramatsu et al., J. Am. Chem. Soc. 132, 15060-15067 (2010). Origins of hole doping and relevant optoelectronic properties of wide gap p-type semiconductor, LaCuOSe
[6] Y. Goto et al., Appl. Phys. Lett. 105, 022104-022107 (2014). Effects of the Cu off-stoichiometry on transport properties of wide gap ptype semiconductor, layered oxysulfide LaCuSO
[7] T. Kato et al., Mater. Sci. Tech. Jpn. 55, 67-71 (2018). Anisotropic thermoelectric exchange properties of high density polycrystalline layered oxychalcogenide, LaCuSeO obtained by uniaxial hot pressing (in Japanese)
[8] N. Azuma et al., Mater. Sci. Tech. Jpn. 58, 64-68 (2021). In-gap-states of a mixed anion layered compound, polycrystalline LaCu1-deltaS0.5Se0.5O (delta~ 0.01) as a degenerate semiconductor (in Japanese)

Synthesis and thermoelectric performance of a layered oxychalcogenide compound LaCuS0.25Se0.75O

Tatsuhide Fujioka, Nobuhiko Azuma, Ryoma Takeuchi, Yoichi Kamihara, Masanori Matoba

The 9th Korea-Japan International Symposium on Materials Science & Technology (KJMST2024) in GCIM2024 （済州） ,

2024年06月

ポスター発表

層状酸化硫化物RETMChO (RE: 希土類, TM: 遷移金属, Ch: カルコゲン)は、p型透明半導体と高効率熱電変換材料などの多様な機能性を示すことが知られている。この報告は、新規に作製されたLaCuS0.25Se0.75Oの多結晶の電気的性質と光学的性質を報告する。LaCuS0.25Se0.75Oはp型で室温で55 Ωcmの導電性を示す半導体であった。この導電性は、仕込み組成に対して意図せずに生じた銅欠陥が正孔を生じることに由来すると考えられる。

Magneto-optical imaging measurement of nominal SmFeAsO0.77H0.12

Tomoki Suemura, Hideo Namita, Ryosuke Sakagami, Tsuyoshi Tamegai, Masanori Matoba, Yoichi Kamihara

The 9th Korea-Japan International Symposium on Materials Science & Technology (KJMST2024) in GCIM2024 （済州） ,

2024年06月

ポスター発表

Synthesis of mixed anion layered compound, polycrystalline LaNiPO samples

Haruyoshi Suzuki, Ryoma Takeuchi, Yuki Ueno, Yoichi Kamihara, Masanori Matoba

The 9th Korea-Japan International Symposium on Materials Science & Technology (KJMST2024) in GCIM2024 （済州） ,

2024年06月

ポスター発表

Evaluation of OER catalystic activity of Bi2Sr2CaCu2O8+x

Masahiro Takeuchi, Hayata Miyamoto, Takahiro Matsumura, Masanori MATOBA, Yoichi KAMIHARA