※ 半角英数字
 年 ~ 
検索結果: 420 件中 1件目~20件目を表示


Initialising ...



Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...



High-temperature short-range order in Mn$$_3$$RhSi

山内 宏樹; Sari, D. P.*; 渡邊 功雄*; 安井 幸夫*; Chang, L.-J.*; 近藤 啓悦; 伊藤 孝; 石角 元志*; 萩原 雅人*; Frontzek, M. D.*; et al.

Communications Materials (Internet), 1, p.43_1 - 43_6, 2020/07



Q dependence of magnetic resonance mode on FeTe$$_{0.5}$$Se$$_{0.5}$$ studied by inelastic neutron scattering

石角 元志*; 樹神 克明; 梶本 亮一; 中村 充孝; 稲村 泰弘; 池内 和彦*; Ji, S.*; 新井 正敏*; 社本 真一

Condensed Matter (Internet), 4(3), p.69_1 - 69_10, 2019/09



Local structure of functional solids

社本 真一

Journal of the Physical Society of Japan, 88(8), p.081008_1 - 081008_11, 2019/08

 被引用回数:1 パーセンタイル:60.52(Physics, Multidisciplinary)

The local structure study reveals important aspects of the physical properties, because it is closely related to the electronic structure. Some neutron total scattering results are reviewed to show the local functional properties of solids from optical recording to negative thermal expansion to Mott transition materials.


Probing the quantum phase transition in Mott insulator BaCoS$$_{2}$$ tuned by pressure and Ni substitution

Guguchia, Z.*; Frandsen, B. A.*; Santos-Cottin, D.*; 社本 真一; Gauzzi, A.*; 植村 泰朋*; 他12名*

Physical Review Materials (Internet), 3(4), p.045001_1 - 045001_9, 2019/04

 被引用回数:0 パーセンタイル:100(Materials Science, Multidisciplinary)



Asymmetrically optimized structure in a high-$$T_{rm c}$$ single unit-cell FeSe superconductor

深谷 有喜; Zhou, G.*; Zheng, F.*; Zhang, P.*; Wang, L.*; Xue, Q.-K.*; 社本 真一

Journal of Physics; Condensed Matter, 31(5), p.055701_1 - 055701_6, 2019/02

 被引用回数:4 パーセンタイル:32.43(Physics, Condensed Matter)



High-energy spin fluctuation in low-T$$_{c}$$ iron-based superconductor LaFePO$$_{0.9}$$

石角 元志*; 社本 真一; 樹神 克明; 梶本 亮一; 中村 充孝; Hong, T.*; Mutka, H.*

Scientific Reports (Internet), 8, p.16343_1 - 16343_6, 2018/11

 被引用回数:2 パーセンタイル:75.88(Multidisciplinary Sciences)



Elastic and dynamical structural properties of La and Mn-doped SrTiO$$_{3}$$ studied by neutron scattering and their relation with thermal conductivities

梶本 亮一; 中村 充孝; 村井 直樹; 社本 真一; 本田 孝志*; 池田 一貴*; 大友 季哉*; 畑 博人*; 江藤 貴弘*; 野田 正亮*; et al.

Scientific Reports (Internet), 8(1), p.9651_1 - 9651_8, 2018/06

 被引用回数:4 パーセンタイル:54.74(Multidisciplinary Sciences)

The electron-doped SrTiO$$_{3}$$ exhibits good thermoelectric properties, which makes this material a promising candidate of an n-type oxide thermoelectric device. Recent studies indicated that only a few percent co-doping of La and Mn in SrTiO$$_{3}$$ substantially reduces the thermal conductivity, thereby greatly improving the thermoelectric figure of merit at room temperature. Our time-of-flight neutron scattering studies revealed that by doping both La and Mn into SrTiO$$_{3}$$, the inelastic scattering spectrum shows a momentum-independent increase in the low-energy spectral weight approximately below 10 meV. The increase in the low-energy spectral weight exhibits a clear correlation with thermal conductivity. The correlation is attributed to dynamical and local structural fluctuations caused by the Jahn-Teller instability in Mn$$^{3+}$$ ions coupled with the incipient ferroelectric nature of SrTiO$$_{3}$$, as the origin of the low thermal conductivity.


Neutron scattering study of yttrium iron garnet

社本 真一; 伊藤 孝; 大西 弘明; 山内 宏樹; 稲村 泰弘; 松浦 直人*; 赤津 光洋*; 樹神 克明; 中尾 朗子*; 茂吉 武人*; et al.

Physical Review B, 97(5), p.054429_1 - 054429_9, 2018/02

 被引用回数:5 パーセンタイル:44.54(Materials Science, Multidisciplinary)



Alternative equation on magnetic pair distribution function for quantitative analysis

樹神 克明; 池田 一貴*; 社本 真一; 大友 季哉*

Journal of the Physical Society of Japan, 86(12), p.124708_1 - 124708_8, 2017/12

 被引用回数:2 パーセンタイル:66.25(Physics, Multidisciplinary)

We derive an alternative equation of magnetic pair distribution function (mPDF) related to the mPDF equation given in a preceding study (B. A. Frandsen, X. Yang, and S. J. L. Billinge, Acta Crystallogr. A, ${bf70}$, 3 (2014)) for quantitative analysis of realistic experimental data. The additional term related to spontaneous magnetization included in the equation is particularly important for the mPDF analysis of ferromagnetic materials. Quantitative estimation of mPDF from neutron diffraction data is also shown. The experimental mPDFs estimated from the neutron diffraction data of the ferromagnet MnSb and the antiferromagnet MnF$$_2$$ are quantitatively consistent with the mPDFs calculated using the presented equation.


Asymmetric structure of germanene on an Al(111) surface studied by total-reflection high-energy positron diffraction

深谷 有喜; 松田 巌*; Feng, B.*; 望月 出海*; 兵頭 俊夫*; 社本 真一

2D Materials (Internet), 3(3), p.035019_1 - 035019_7, 2016/09

 被引用回数:25 パーセンタイル:20.73(Materials Science, Multidisciplinary)



Local structural analysis of half-metallic ferromagnet CrO$$_2$$

樹神 克明; 池田 一貴*; 礒部 正彦*; 武田 晃*; 伊藤 正行*; 上田 寛*; 社本 真一; 大友 季哉*

Journal of the Physical Society of Japan, 85(9), p.094709_1 - 094709_5, 2016/09

 被引用回数:1 パーセンタイル:83.63(Physics, Multidisciplinary)

We have performed powder neutron diffraction on the half-metallic ferromagnet CrO$$_2$$ which has a rutile-type crystal structure with a tetragonal unit cell. Although the powder diffraction pattern can be fitted by the reported crystal structure including a single Cr site, the atomic pair distribution function (PDF) can be fitted by the structural model with an orthorhombic unit cell including two kinds of inequivalent Cr sites. The difference between the valences of the two inequivalent Cr sites, $$delta$$ of Cr$$^{+4pmdelta}$$, estimated from the local structural parameters is about 0.06. The shapes of the two CrO$$_6$$ octahedra are slightly different, suggesting the short-range orbital ordering of the Cr 3$$d$$ orbitals. The lattice distortion and the improvement of the fitting to the PDF obtained using the locally distorted structure model are apparent in the region below about 10 ${AA}$, suggesting that the domain size or correlation length of the locally distorted structure is about 10 ${AA}$, roughly corresponding to the size of two unit cells.


Spacing between graphene and metal substrates studied with total-reflection high-energy positron diffraction

深谷 有喜; 圓谷 志郎; 境 誠司; 望月 出海*; 和田 健*; 兵頭 俊夫*; 社本 真一

Carbon, 103, p.1 - 4, 2016/07

 被引用回数:12 パーセンタイル:42.16(Chemistry, Physical)



Resonant inelastic X-ray scattering study of entangled spin-orbital excitations in superconducting PrFeAsO$$_{0.7}$$

野村 拓司*; 原田 慈久*; 丹羽 秀治*; 石井 賢司*; 石角 元志*; 社本 真一; Jarrige, I.*

Physical Review B, 94(3), p.035134_1 - 035134_9, 2016/07

 被引用回数:7 パーセンタイル:55.84(Materials Science, Multidisciplinary)



Local lattice distortion caused by short-range charge ordering in transition metal oxides

樹神 克明; 井川 直樹; 社本 真一; 池田 一貴*; 大下 英敏*; 金子 直勝*; 大友 季哉*; 鈴谷 賢太郎; 星川 晃範*; 石垣 徹*

JPS Conference Proceedings (Internet), 8, p.034002_1 - 034002_6, 2015/09

Cubic spinel compound LiMn$$_2$$O$$_4$$ with the mixed valence of Mn$$^{3.5+}$$ has non-metallic conductivity. The local structure determined by the PDF analysis has an orthorhombic lattice distortion and includes inequivalent Mn$$^{3+}$$ and Mn$$^{4+}$$ sites. YBaCo$$_2$$O$$_5$$ also exhibits non-metallic conductivity although the Co has the mixed valence of +2.5 above 220 K which corresponds with charge ordering temperature. The PDF obtained at 450 K is not reproduced by the PDF calculated for the averaged structure and can be reproduced by the PDF calculated for the structure model corresponding to the charge ordering state. These results suggest that the valence electrons are localized with short-range periodicity, resulting in the non-metallic conductivities in these materials.


Precise measurement of acoustic phonons in PrFeAsO$$_{1-y}$$

福田 竜生; Baron, A. Q. R.*; 内山 裕士*; 中村 博樹; 石角 元志*; 町田 昌彦; 社本 真一

SPring-8/SACLA利用研究成果集(Research Report) (インターネット), 3(2), p.290 - 293, 2015/07

Using inelastic X-ray scattering (IXS), we investigated acoustic phonons of PrFeAsO$$_{1-y}$$ precisely in order to select between two different models based on first principles calculations: the in-plane soft and clipped model. These models predict slightly different phonon intensities, and, in particular, different contamination of the longitudinal acoustic (LA) phonon spectra by transverse acoustic (TA) phonon modes. We were able to reduce the contamination with improved ${bfit Q}$ resolution, but the data quality was not sufficient to clearly decide between our models. Based on $$Q$$ dependence there appears to be slightly better agreement with the in-plane soft model at room temperature.


Anisotropic magnetic form factor in a detwinned single crystal of BaFe$$_2$$As$$_2$$

樹神 克明; 石角 元志*; 脇本 秀一; 木方 邦宏*; Lee, C.-H.*; 伊豫 彰*; 永崎 洋*; 社本 真一

Physical Review B, 90(14), p.144510_1 - 144510_5, 2014/10

 被引用回数:1 パーセンタイル:93.63(Materials Science, Multidisciplinary)

We have performed neutron diffraction measurements at 12K on a single crystal of BaFe$$_2$$As$$_2$$, which serves as the parent compound of iron-based superconductor. To investigate the in-plane anisotropy of the magnetic form factor in the antiferromagnetic phase, the single crystal was detwinned. The magnetic structure factor and magnetic form factor are well explained by the spin densities comprising $$3d_{yz}$$ electrons with a fraction of approximately 40% and electrons in the other four $$3d$$ orbitals each with a fraction of approximately 15%. It is a direct observation of the largely anisotropic spin density relative to the small orthorhombic lattice distortion, $$(a-b)/(a+b)$$ $$sim$$ 0.3%.


Superconductivity in noncentrosymmetric iridium silicide Li$$_2$$IrSi$$_3$$

Pyon, S.*; 工藤 一貴*; 松村 純一*; 石井 博文*; 松尾 元太*; 野原 実*; 北條 元*; 岡 研吾*; 東 正樹*; Garlea, V. O.*; et al.

Journal of the Physical Society of Japan, 83(9), p.093706_1 - 093706_5, 2014/09

 被引用回数:18 パーセンタイル:21.91(Physics, Multidisciplinary)

The effects of lithium absorption on the crystal structure and electronic properties of IrSi$$_3$$, a binary silicide with a noncentrosymmetric crystal structure, were studied. X-ray and neutron diffraction experiments revealed that hexagonal IrSi$$_3$$ (space group $$P6_3mc$$) transforms into trigonal Li$$_2$$IrSi$$_3$$ (space group $$P31c$$) upon lithium absorption. The structure of Li$$_2$$IrSi$$_3$$ is found to consist of a planar kagome network of silicon atoms with Li and Ir spaced at unequal distances between the kagome layers, resulting in a polar structure along the c-axis. Li$$_2$$IrSi$$_3$$ exhibited type-II superconductivity with a transition temperature $$T_{rm c}$$ of 3.8 K, displaying a structure type that no previous superconductors have been reported to have.


Local structural analysis by using atomic pair distribution function on mixed valence compound LiMn$$_2$$O$$_4$$

樹神 克明; 井川 直樹; 社本 真一; 池田 一貴*; 大下 英敏*; 金子 直勝*; 大友 季哉*; 鈴谷 賢太郎; 星川 晃範*; 石垣 徹*

JPS Conference Proceedings (Internet), 3, p.013012_1 - 013012_6, 2014/06

LiMn$$_2$$O$$_4$$ has a cubic spinel structure with a single Mn site whose valence is +3.5. Below about 260 K, the compound exhibits a charge ordering and has inequivalent Mn sites with valences of +3 and +4. However, even in the cubic phase without the charge ordering, temperature dependence of the electrical conductivity is non-metallic. We have performed PDF (atomic pair distribution function) analysis on powder neutron diffraction data of LiMn$$_2$$O$$_4$$ obtained above 300 K where the compound has cubic structure. The local structure determined by PDF analysis has an orthorhombic lattice distortion and includes the inequivalent Mn sites with valences of +3 and +4 up to, at least, about 450 K. These results indicate that valence electrons are localized at Mn sites with short range periodicity, resulting in the non-metallic electrical conductivity. It can be regarded as a glass state of valence electrons whereas a charge ordering can be regarded as a crystallization of valence electrons.


Evidence of electronic polarization of the As ion in the superconducting phase of F-doped LaFeAsO

Kim, J.*; 藤原 明比古*; 澤田 智弘*; Kim, Y.*; 杉本 邦久*; 加藤 健一*; 田中 宏志*; 石角 元志*; 社本 真一; 高田 昌樹*

IUCrJ, 1(3), p.155 - 159, 2014/05

 被引用回数:2 パーセンタイル:73.79(Chemistry, Multidisciplinary)



2D neutron diffraction imaging on an ammonite

社本 真一; 樹神 克明; 伊巻 正*; 中谷 健; 大下 英敏*; 金子 直勝*; 増子 献児*; 坂本 健作; 山口 憲司; 鈴谷 賢太郎; et al.

JPS Conference Proceedings (Internet), 1, p.014011_1 - 014011_5, 2014/03


420 件中 1件目~20件目を表示