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藤原 秀紀*; 中谷 泰博*; 荒谷 秀和*; 金井 惟奈*; 山神 光平*; 濱本 諭*; 木須 孝幸*; 山崎 篤志*; 東谷 篤志*; 今田 真*; et al.
Physical Review B, 108(16), p.165121_1 - 165121_10, 2023/10
被引用回数:0 パーセンタイル:0.00(Materials Science, Multidisciplinary)We report the ground-state symmetry of the Ce 4 states in the heavy-fermion superconductor CeNi
Ge
, yielding anisotropic
hybridization between the Ce 4
states and conducting electrons. By analyzing linear dichroism in soft X-ray absorption and core-level hard X-ray photoemission spectra, the 4
symmetry is determined as
-type
, promoting predominant hybridization with the conducting electrons originating from the Ge site. The band structures probed by soft X-ray angle-resolved photoemission indicates that the Ge 4
components contribute to the band renormalization through the anisotropic hybridization effects, suggesting that the control of the electronic structures of Ge orbital gives an impact to achieve the exotic phenomena in CeNi
Ge
.
木村 健太*; 八木 直輝*; 長谷川 舜介*; 萩原 雅人; 三宅 厚志*; 徳永 将史*; Cao, H.*; 益田 隆嗣*; 木村 剛*
Inorganic Chemistry, 60(20), p.15078 - 15084, 2021/10
被引用回数:2 パーセンタイル:6.68(Chemistry, Inorganic & Nuclear)In materials showing a linear magnetoelectric (ME) effect, unconventional functionalities can be anticipated such as electric control of magnetism and nonreciprocal optical responses. Thus, the search of new linear ME materials is of interest in materials science. Here, using a recently proposed design principle of linear ME materials, which is based on the combination of local structural asymmetry and collinear antiferromagnetism, we demonstrate that an anion-deficient fluorite derivative MnTa
O
is a new linear ME material. This is evidenced by the onset of magnetic-field-induced electric polarization in its collinear antiferromagnetic phase below
= 24 K. Furthermore, we also find an antiferroelectric-like phase transition at
= 55 K, which is attributable to an off-center displacement of magnetic Mn
ions. The present study shows that Mn
Ta
O
is a rare material that exhibits both ME and antiferroelectric-like transitions. Thus, Mn
Ta
O
may provide an opportunity to investigate the physics associated with complicated interactions between magnetic (spin) and electric dipole degrees of freedom.
松本 裕司*; 芳賀 芳範; 山本 悦嗣; 竹内 徹也*; 三宅 厚志*; 徳永 将史*
Journal of the Physical Society of Japan, 90(7), p.074707_1 - 074707_6, 2021/07
被引用回数:1 パーセンタイル:12.31(Physics, Multidisciplinary)A uranium intermetallic compound UPt
Ga
was successfully synthesized. This compound crystallizes in the hexagonal Sc
Fe
Si
-type structure. Antiferromagnetic transition with highly magnetic anisotropy was established by the physical property measurements.
奥谷 顕*; 大西 弘明; 木村 尚次郎*; 竹内 徹也*; 木田 孝則*; 森 道康; 三宅 厚志*; 徳永 将史*; 金道 浩一*; 萩原 政幸*
Journal of the Physical Society of Japan, 90(4), p.044704_1 - 044704_9, 2021/04
被引用回数:4 パーセンタイル:39.84(Physics, Multidisciplinary)The high-field multifrequency electron spin resonance (ESR), the magnetization, and the specific heat of single crystals of BaCoV
O
(a quasi-one-dimensional Ising-like antiferromagnet with
) were measured in two different transverse magnetic fields:
and
. A softening of the lowest ESR mode was observed near the saturation field of the magnetization around 40 T in
, whereas it occurs around 10 T in
, far below the saturation field. These observations were reproduced by numerical calculations using the density-matrix renormalization group methods, including the staggered magnetic fields induced by a uniform external magnetic field and the interchain magnetic exchange interaction. We found that the directional dependence of the lowest mode originates mainly from the remarkable angular dependence of the induced magnetic field. The interchain interaction is also quantitatively important for reproducing the experimental results. The directional dependence of the lowest mode is demonstrated by the particle-hole excitation of spinons using the Jordan-Wigner transformation.
清水 悠晴*; 三宅 厚志*; Maurya, A.*; 本多 史憲*; 仲村 愛*; 佐藤 芳樹*; Li, D.*; 本間 佳哉*; 横山 淳*; 徳永 陽; et al.
Physical Review B, 102(13), p.134411_1 - 134411_11, 2020/10
被引用回数:7 パーセンタイル:36.02(Materials Science, Multidisciplinary)The physical properties of URhSn with quasi-kagome structure are studied using single-crystalline samples via electrical resistivity, magnetic susceptibility, heat capacity, thermal expansion, and high-field magnetization measurements. We found remarkable magnetic anisotropy in the ferromagnetic state below 16 K as well as in the ordered state between 16 K and 54 K.
Pospil, J.*; 芳賀 芳範; 三宅 厚志*; 神戸 振作; 徳永 陽; 徳永 将史*; 山本 悦嗣; Proschek, P.*; Voln
, J.*; Sechovsk
, V.*
Physical Review B, 102(2), p.024442_1 - 024442_13, 2020/07
被引用回数:7 パーセンタイル:36.02(Materials Science, Multidisciplinary)Alloying study of ferromagnetic superconductors URhGe and UCoGe is reported. The Curie temperature shows a maximum at Rh concentration = 0.4 in UCo
Rh
Ge. Magnetic characteristices in low- and high-
regions are significantly different each other. The relationship between magnetism and superconductivity are discussed.
Fogh, E.*; 木原 工*; Toft-Petersen, R.*; Bartkowiak, M.*; 鳴海 康雄*; Prokhnenko, O.*; 三宅 厚志*; 徳永 将史*; 及川 健一; Srensen, M. K.*; et al.
Physical Review B, 101(2), p.024403_1 - 024403_12, 2020/01
被引用回数:19 パーセンタイル:70.44(Materials Science, Multidisciplinary)Neutron diffraction with static and pulsed magnetic fields is used to directly probe the magnetic structures in LiNiPO up to 25 T and 42 T, respectively. By combining these results with magnetometry and electric polarization measurements under pulsed fields, the magnetic and magnetoelectric phases are investigated up to 56 T applied along the easy
axis. In addition to the already known transitions at lower fields, three new ones are reported at 37.6, 39.4, and 54 T. Ordering vectors are identified with Q
= (0,
, 0) in the interval 37.6 - 39.4 T and Q
= (0, 0, 0) in the interval 39.4 - 54 T. A quadratic magnetoelectric effect is discovered in the Q
= (0, 0, 0) phase and the field dependence of the induced electric polarization is described using a simple mean-field model. The observed magnetic structure and magnetoelectric tensor elements point to a change in the lattice symmetry in this phase. We speculate on the possible physical mechanism responsible for the magnetoelectric effect in LiNiPO
.
吉田 剛*; 二宮 和彦*; 稲垣 誠*; 髭本 亘; Strasser, P.*; 河村 成肇*; 下村 浩一郎*; 三宅 康博*; 三浦 太一*; 久保 謙哉*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 320(2), p.283 - 289, 2019/05
被引用回数:4 パーセンタイル:35.14(Chemistry, Analytical)分子へのミュオン捕獲過程における価電子の役割をカスケード計算を補助的に用いることで求めた。低運動量ミュオン大気圧の期待標的に打ち込み、ライマンおよびバルマー系列のミュオンX線を測定することにより初期状態を求めた。この結果から、大きな軌道角運動量を持つ軌道への捕獲に際しては炭素中の孤立した対電子が大きな役割を果たしていることを提案した。
二宮 和彦*; 伊藤 孝; 髭本 亘; 河村 成肇*; Strasser, P.*; 長友 傑*; 下村 浩一郎*; 三宅 康博*; 喜多 真琴*; 篠原 厚*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 319(3), p.767 - 773, 2019/03
被引用回数:12 パーセンタイル:74.06(Chemistry, Analytical)Per-atom muon capture ratios are precisely determined from characteristic muonic X-ray measurements of three nitrogen oxide samples (NO, NO, and NO
) at pressures below 100 kPa. A higher density of covalent electrons at the N atoms relative to the O atoms is required if we explain the experimental results using the proposed muon capture models. From molecular orbit calculations, we found that the electron distributions of only the highest occupied molecular orbitals (HOMO) are dominant at the N atoms, and the electrons in the HOMO significantly contribute to the muon capture phenomena in the nitrogen oxide molecules.
Li, D. X.*; 本多 史憲*; 三宅 厚志*; 本間 佳哉*; 芳賀 芳範; 仲村 愛*; 清水 悠晴*; Maurya, A.*; 佐藤 芳樹*; 徳永 将史*; et al.
Physical Review B, 99(5), p.054408_1 - 054408_9, 2019/02
被引用回数:7 パーセンタイル:32.25(Materials Science, Multidisciplinary)Physical properties of the single-crystalline UIr
Si
, a new ternary uranium compound with U
Co
Si
-type orthorhombic structure, are investigated by means of magnetic susceptibility, specific heat and electrical resistivity. This compound undergoes an antiferromagnetic transition followed by a first-order phase transition at lower temperature. A possible mechanism of the first-order transition is the occurrence of a magnetic magnetic quadrupolar order, resulting from the quasi-one-dimensional uranium zigzag chain.
Pospil, J.*; 芳賀 芳範; 小濱 芳允*; 三宅 厚志*; 神戸 振作; 立岩 尚之; Vali
ka, M.*; Proschek, P.*; Prokle
ka, J.*; Sechovsk
, V.*; et al.
Physical Review B, 98(1), p.014430_1 - 014430_7, 2018/07
被引用回数:16 パーセンタイル:56.99(Materials Science, Multidisciplinary)The metamagnetic transition between the antiferromagnetic and paramagnetic state in UIrGe has been studied at various temperatures by magnetization, heat capacity, and magnetocaloric effect measurements on a single crystal in static and pulsed magnetic fields applied along the orthorhombic axis. The first-order transition is accompanied by a dramatic increase of the Sommerfeld coefficient. A tentative scenario explaining these anomalies by antiferromagnetic correlations or short-range order in the paramagnetic state is discussed.
足立 泰平*; 池戸 豊*; 西山 樟生*; 薮内 敦*; 長友 傑*; Strasser, P.*; 伊藤 孝; 髭本 亘; 小嶋 健児*; 牧村 俊助*; et al.
JPS Conference Proceedings (Internet), 8, p.036017_1 - 036017_4, 2015/09
We report on the tuning of the ultra-slow muon beam line at J-PARC MUSE using Li impurities in a tungsten muonium production target in place of positive muons. Li ions were evaporated from the tungsten target by heating it up to 2000K and were transported in the ultra-slow muon beam line. The Li ion beam was monitored by micro channel plates installed at several points in the beam line. The Li beam was successfully transported to the end of the beam line after optimization of beam line parameters.
二宮 和彦*; 久保 謙哉*; 長友 傑*; 髭本 亘; 伊藤 孝; 河村 成肇*; Strasser, P.*; 下村 浩一郎*; 三宅 康博*; 鈴木 栄男*; et al.
Analytical Chemistry, 87(9), p.4597 - 4600, 2015/05
被引用回数:28 パーセンタイル:69.71(Chemistry, Analytical)Elemental analysis of materials is fundamentally important to science and technology. Many elemental analysis methods have been developed, but three-dimensional nondestructive elemental analysis of bulk materials has remained elusive. Recently, we developed a nondestructive depth-profiling elemental analysis method after a decade of research. This new method utilizes a new type of probe; a negative muon particle and high-energy muonic X-rays emitted after the muon stops in a material. We performed elemental depth profiling on an old Japanese gold coin (Tempo-Koban) using a low-momentum negative muon beam and successfully determined that the Au concentration in the coin gradually decreased with depth over a micrometer length scale.
本多 史憲*; 広瀬 雄介*; 三宅 厚志*; 水牧 仁一朗*; 河村 直己*; 筒井 智嗣*; 綿貫 徹; 渡辺 真仁*; 竹内 徹也*; 摂待 力生*; et al.
Journal of Physics; Conference Series, 592(1), p.012021_1 - 012021_5, 2015/03
被引用回数:3 パーセンタイル:70.20(Physics, Atomic, Molecular & Chemical)重い電子系化合物YbTZn
(T: Rh and Ir)について、X線吸収分光法によりYb価数観察を行った。いずれの化合物でもYb価数は温度依存性を示し、約100K以下で冷却とともにYb価数が減少する変化が見られた。これは、同型化合物であるYbCo
Zn
において温度依存性が見られないこととは対照的な結果である。
青木 大*; Taupin, M.*; Paulsen, C.*; Hardy, F.*; Taufour, V.*; 小手川 恒*; Hassinger, E.*; Malone, L.*; 松田 達磨; 三宅 厚志*; et al.
Journal of the Physical Society of Japan, 81(Suppl.B), p.SB002_1 - SB002_6, 2012/12
被引用回数:3 パーセンタイル:25.89(Physics, Multidisciplinary)We review our recent studies on ferromagnetic superconductors, UGe2, URhGe, and UCoGe. We focus on experimental results of URhGe and UCoGe in which the superconductivity occurs already at ambient pressure. The huge upper critical field on UCoGe for the field along the hard magnetization axis (
-axis) is confirmed by the AC susceptibility measurements by the fine tuning of field angle. Contrary to the huge
along the hard-magnetization axis,
along the easy-magnetization axis (
-axis) is relatively small in value. However, the initial slope of
, namely
/
(
0) both in UCoGe and in URhGe indicates the large value, which can be explained by the magnetic domain effect detected in the magnetization measurements. The specific heat measurements using a high quality single crystal of UCoGe demonstrate the bulk superconductivity, which is extended under magnetic field for the field along
-axis.
二宮 和彦; 長友 傑*; 久保 謙哉*; 伊藤 孝; 髭本 亘; 喜多 真琴*; 篠原 厚*; Strasser, P.*; 河村 成肇*; 下村 浩一郎*; et al.
Bulletin of the Chemical Society of Japan, 85(2), p.228 - 230, 2012/02
被引用回数:29 パーセンタイル:61.16(Chemistry, Multidisciplinary)負ミュオンが物質中に停止しミュオン原子が形成すると、高エネルギーで透過力の強いミュオン特性エックス線が放出される。本研究ではミュオン特性エックス線測定による非破壊元素分析技術の開発を行った。元素の構成比が既知の青銅の標準試料に対して負ミュオンの照射を行い、ミュオン原子が形成した後に放出されるミュオン特性エックス線の強度から、青銅に含まれる元素構成を決定するための検量線を作成した。この関係を用いて成分が未知の中国の古銭について負ミュオンの照射を行い、得られたミュオン特性エックス線スペクトルから古銭の元素の構成比を非破壊で決定した。
青木 大*; Hardy, F.*; 三宅 厚志*; Taufour, V.*; 松田 達磨; Flouquet, J.*
Comptes Rendus Physique, 12(5-6), p.573 - 583, 2011/06
被引用回数:38 パーセンタイル:81.90(Astronomy & Astrophysics)Thanks to the discovery in the last decade of three uranium ferromagnetic superconductors, UGe, URhGe and UCoGe, the fascinating aspects of the interplay between the triplet state of Cooper pairing and ferromagnetism have emerged. Furthermore, as the ferromagneticproperties in the normal state are quite different with respect to the proximity of the ferromagnetic-paramagnetic instabilities, the feedback with the coexistence of superconductivity gives rise to quite different boundaries in pressure and magnetic field. Specialattention is given on the location of the materials with respect to the tricriticality and on the reinforcement of SC in a transverse field response with respect to the direction of the FM sublattice magnetization.
佐藤 翔一*; 市村 真*; 山口 裕資*; 片野 誠*; 今井 康隆*; 村上 達也*; 三宅 勇一郎*; 横山 拓郎*; 森山 伸一; 小林 貴之; et al.
Plasma and Fusion Research (Internet), 5, p.S2067_1 - S2067_4, 2010/12
JT-60Uで観測されるイオンサイクロトロン放射(ICE)のなかで、入射したDビームに起因するICE(D)と核反応生成(FP)イオンに起因するICEでは、トロイダル方向の波数が異なり、FPイオンによるICEは有限な波数を持つことがこれまでに観測されている。この性質を利用して、ICE(D)の2倍高調波と分離してICE(H)を同定した。ICE(H)が観測される条件を明らかにすることを目的として、実験条件の特定とEPOCコードを用いて軌道の計算をしている。
松井 義典; 高橋 広幸; 山本 雅也; 仲田 祐仁; 吉武 庸光; 阿部 和幸; 吉川 勝則; 岩松 重美; 石川 和義; 菊地 泰二; et al.
JAEA-Technology 2009-072, 144 Pages, 2010/03
日本原子力研究開発機構は、平成17年10月に日本原子力研究所と核燃料サイクル開発機構との統合によって誕生した。この統合を最大限に利用したプロジェクトが、旧電源開発促進対策特別会計法及び特別会計に関する法律(エネルギー対策特別会計)に基づく文部科学省からの受託事業「長寿命プラント照射損傷管理技術に関する研究開発」である。この「長寿命プラント照射損傷管理技術に関する研究開発」において、材料の照射損傷評価指標の確立に重要な、世界で類のない、高速実験炉「常陽」と研究用原子炉であるJRR-3を利用した組合せ照射材を平成18年から平成19年の約2年間の短期間で取得した。本報告は、これら常陽,JRR-3の実験炉施設及びWASTEF, JMTRホットラボ,MMF, FMFのホット施設を利用した組合せ照射における作業計画から作業結果及び照射試験における照射温度と照射量の評価をまとめたものである。
三宅 厚志*; 金政 泰介*; 八木 良平*; 加賀山 朋子*; 清水 克哉*; 芳賀 芳範; 大貫 惇睦
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.e222 - e224, 2007/03
アルファマンガンの単結晶試料を用いて高圧下電気抵抗測定を行った。アルファマンガンは転移温度95Kの反強磁性物質であり、結晶学的に異なる4つのマンガンサイトがある。アルファマンガンの磁気転移温度は加圧とともに低温側にシフトし、転移温度における鋭い抵抗異常は鈍いkinkへと変化し、異なる磁気秩序相が高圧下で形成されていることを示唆された。1.9GPaの相境界では、残留抵抗が急減に減少し、電気抵抗のの係数Aがピークを形成することが明らかにされた。