Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 45

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Three-dimensional bulk Fermi surfaces and Weyl crossings of Co$$_2$$MnGa thin films underneath a protection layer

Kono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki; Muro, Takayuki*; Goto, Kazuki*; Sakuraba, Yuya*; Umetsu, Rie*; Kimura, Akio*

Physical Review B, 104(19), p.195112_1 - 195112_8, 2021/11

Angle-resolved photoelectron spectroscopy utilizing soft X-ray synchrotron radiation was applied to Heusler-type Co$$_2$$MnGa thin films that have a 1-nm Al capping layer. The bulk Fermi surfaces and band structures varied along the out-of-plane momentum, stemming from the three-dimensional crystal structure, in the absence of any in situ surface treatment. In addition, there were characteristic intersecting bands (Weyl cones), with crossing points near the Fermi level, which were consistent with computed results. The Weyl cones are of bulk origin and are responsible for the high anomalous Nernst and the anomalous Hall coefficients. A close comparison of the experimental band structures in Co$$_2$$MnGe and Co$$_2$$MnGa indicated that the rigid band picture is valid in both alloys and that fine carrier tuning is possible by replacing Ga with Ge to improve the anomalous conductivity.

Journal Articles

Element-specific density of states of Co$$_{2}$$MnGe revealed by resonant photoelectron spectroscopy

Kono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki*; Miyamoto, Koji*; Muro, Takayuki*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; et al.

Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10

 Times Cited Count:2 Percentile:22.92(Materials Science, Multidisciplinary)

Journal Articles

Experimental determination of the topological phase diagram in Cerium monopnictides

Kuroda, Kenta*; Ochi, Masayuki*; Suzuki, Hiroyuki*; Hirayama, Motoaki*; Nakayama, Mitsuhiro*; Noguchi, Ryo*; Bareille, C.*; Akebi, Shuntaro*; Kunisada, So*; Muro, Takayuki*; et al.

Physical Review Letters, 120(8), p.086402_1 - 086402_6, 2018/02

 Times Cited Count:24 Percentile:89.19(Physics, Multidisciplinary)

Journal Articles

Interaction of rare earth elements and components of the Horonobe deep groundwater

Kirishima, Akira*; Kuno, Atsushi*; Amamiya, Hiroki; Kubota, Takumi*; Kimuro, Shingo*; Amano, Yuki; Miyakawa, Kazuya; Iwatsuki, Teruki; Mizuno, Takashi; Sasaki, Takayuki*; et al.

Chemosphere, 168, p.798 - 806, 2017/02

 Times Cited Count:1 Percentile:5.42(Environmental Sciences)

For better understanding of the migration behavior of minor actinides (MA) in deep groundwater, the interaction of doped rare earth elements (REEs) and components in Horonobe deep groundwater was studied. Appx. 10 ppb of rare earth elements, i.e., Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm and Yb were doped to the sample groundwater collected from a packed sections in borehole drilled from 140 m depth experiment drift of Horonobe underground research laboratory (URL), Hokkaido, Japan. Then, that groundwater was sequentially filtrated by 0.2 micron pore filter, 10 kDa, 3 kDa and 1 kDa of nominal molecular weight limit (NMWL) ultrafilters by keeping inert condition. After that, the filtrate solutions were analyzed by ICP-MS to determine the concentrations of retained REEs at each filtration steps, while the used filters were analyzed by the neutron activation analysis (NAA) and TOF-SIMS element mapping to know the amount and chemical speciation of trapped fraction of the REEs on each filter. A remarkable relation between the retention ratios of REEs in the filtrate solutions and the ionic radius was observed, i.e., smaller rare earth element solves more in liquid phase under the Horonobe groundwater condition. NAA and TOF-SIMS analyses revealed that certain portions of REEs were trapped by 0.2 micron pore filters as rare earth phosphates which corresponded with the predicted predominant species by a chemical equilibrium calculation for the Horonobe groundwater condition, while small portions of colloidal REEs were trapped by 10 kDa and 3 kDa NMWL ultrafilters. The result suggested that phosphate anion plays an important role in the chemical behavior of REEs in saline (seawater based) groundwater, which could be referred for the prediction of migration behavior of trivalent actinide released from the repository of radioactive waste in far future.

Journal Articles

Nitrogen $$K$$-edge soft X-ray natural circular dichroism of histidine thin film

Izumi, Yudai; Tanaka, Masahito*; Tanigawa, Yoshiaki*; Tanabe, Maiko*; Momoki, Yohei*; Iwai, Miki*; Takenaka, Shun*; Ishiyama, Kimihiro*; Kuroki, Misa*; Muro, Takayuki*; et al.

Journal of Physics; Conference Series, 502(1), p.012038_1 - 012038_4, 2014/04

 Times Cited Count:1 Percentile:60.31

Journal Articles

Characteristic oxygen $$K$$-edge circular dichroism spectra of amino acid films by improved measurement technique

Izumi, Yudai*; Tanabe, Maiko*; Imazu, Akiko*; Mimoto, Aki*; Tanaka, Masahito*; Agui, Akane; Muro, Takayuki*; Nakagawa, Kazumichi*

Journal of Chemical Physics, 138(7), p.074305_1 - 074305_10, 2013/02

 Times Cited Count:6 Percentile:24.61(Chemistry, Physical)

no abstracts in English

Journal Articles

Electronic structure of aluminium trihydride studied using soft X-ray emission and absorption spectroscopy

Takeda, Yukiharu; Saito, Yuji; Saito, Hiroyuki; Machida, Akihiko; Aoki, Katsutoshi; Yamagami, Hiroshi; Muro, Takayuki*; Kato, Yukako*; Kinoshita, Toyohiko*

Physical Review B, 84(15), p.153102_1 - 153102_4, 2011/10

 Times Cited Count:7 Percentile:35.48(Materials Science, Multidisciplinary)

We have performed soft X-ray emission spectroscopy (SXES) and soft X-ray absorption spectroscopy (SXAS) experiments on aluminum hydride $${alpha}$$-AlH$$_{3}$$. The occupied and unoccupied electronic states of the Al 3$$p$$ partial density of states are obtained experimentally. By comparing the data from Al metal and $${alpha}$$-AlH$$_{3}$$, a band gap with a few eV is found for $${alpha}$$-AlH$$_{3}$$. In addition, the occupied states of $${alpha}$$-AlH$$_{3}$$ have a larger spectral intensity than that of Al metal, indicating an increase in the number of electrons with the Al 3$$p$$ character through Al-H bond formations. The results of a band-structure calculation account for the formation of the energy gap and the increase of the Al 3$$p$$ electrons qualitatively. This suggests that a covalent-like nature is important to the Al-H bond in $${alpha}$$-AlH$$_{3}$$.

Journal Articles

Electronic structure of lithium amide

Kamakura, Nozomu; Takeda, Yukiharu; Saito, Yuji; Yamagami, Hiroshi; Tsubota, Masami*; Paik, B.*; Ichikawa, Takayuki*; Kojima, Yoshitsugu*; Muro, Takayuki*; Kato, Yukako*; et al.

Physical Review B, 83(3), p.033103_1 - 033103_4, 2011/01

 Times Cited Count:5 Percentile:27.56(Materials Science, Multidisciplinary)

The electronic structure of lithium amide, which is lightweight complex hydride expected as a high-capacity hydrogen storage material, is investigated by N 1$$s$$ soft X-ray emission spectroscopy (XES) and absorption spectroscopy (XAS). The overall feature of the electronic structure of lithium amide by the XES and XAS is consistent with the band calculation, while the strongly hybridized state with H 1$$s$$ is located at higher binding energy than the band calculation.

Journal Articles

Radiation-induced chemical evolution of biomolecules

Nakagawa, Kazumichi*; Matsui, Takahiro*; Izumi, Yudai*; Agui, Akane; Tanaka, Masahito*; Muro, Takayuki*

Radiation Physics and Chemistry, 78(12), p.1198 - 1201, 2009/12

 Times Cited Count:3 Percentile:26.15(Chemistry, Physical)

Chemical-evolution in glycilglycine (Gly2) films irradiated by 146 nm light was studied. It was found that quantum efficiency of chemical evolution from Gly2 to glycilglycilglycine (Gly3) is smaller than that to glycilglycilglycilglycine (Gly4) due to the multiple step of reaction. From natural circular dichroism spectra measurements for serine and alanine films, we found the splitting of 1s$$rightarrow$$$$pi$$$$^{*}$$ transitions in the energy region of oxygen 1s.

Journal Articles

Measurement and comparison of absolute value of soft X-ray natural circular dichroism of serine and alanine

Izumi, Yudai*; Imazu, Akiko*; Mimoto, Aki*; Tanaka, Masafumi*; Nakagawa, Kazumichi*; Tanaka, Masahito*; Agui, Akane; Muro, Takayuki*

Journal of Physics; Conference Series, 190, p.012209_1 - 012209_4, 2009/11

 Times Cited Count:6 Percentile:84.09

Soft X-ray natural circular dichroism spectra of serine and alaninethin films, were measured in absolute value with the focus at the oxygen 1s to $$pi$$$$^{*}$$ transition of COO$$^{-}$$. The soft X-ray natural circular dichroism spectra intensity of L-Ala was about ten times as large as that of L-Ser. Those differences would reflect the chiral environment of the core hole oxygen atoms of COO$$^{-}$$.

Journal Articles

Photoemission study of (V$$_{1-x}$$$$M$$$$_{x}$$)$$_{2}$$O$$_{3}$$ ($$M$$=Cr,Ti)

Mo, S.-K.*; Kim, H.-D.*; Denlinger, J. D.*; Allen, J. W.*; Park, J.-H.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Suga, Shigemasa*; Saito, Yuji; Muro, Takayuki*; et al.

Physical Review B, 74(16), p.165101_1 - 165101_12, 2006/10

 Times Cited Count:44 Percentile:84.54(Materials Science, Multidisciplinary)

We present high-resolution bulk-sensitive photoemission spectra of (V$$_{1-x}$$$$M$$$$_{x}$$)$$_{2}$$O$$_{3}$$ ($$M$$=Cr,Ti). The measurements were made for the paramagnetic metal (PM), paramagnetic insulator (PI), and antiferromagnetic insulator (AFI) phases of (V$$_{1-x}$$$$M$$$$_{x}$$)$$_{2}$$O$$_{3}$$. In the PM phase, we observe a prominent quasiparticle peak in general agreement with theory, which combines dynamical mean-field theory with the local density approximation. For both the PI and AFI phases, the vanadium 3$$d$$ parts of the valence spectra are not simple one peak structures. For the PI phase, there is not yet a good theoretical understanding of these structures. Spectra taken in the same phases with different compositions show interesting monotonic changes as the dopant concentration increases, regardless of the dopant species. With increased Cr-doping, the AFI phase gap decreases and the PI phase gap increases.

Journal Articles

Soft-X-ray high-resolution photoemission study on the valence transitions in YbInCu$$_{4}$$

Sato, Hitoshi*; Yoshikawa, Kunta*; Hiraoka, Koichi*; Arita, Masashi*; Fujimoto, Koji*; Kojima, Kenichi*; Muro, Takayuki*; Saito, Yuji; Sekiyama, Akira*; Suga, Shigemasa*; et al.

Physical Review B, 69(16), p.165101_1 - 165101_6, 2004/04

 Times Cited Count:31 Percentile:77.88(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Resonant photoemission spectroscopy study of impurity-induced melting in Cr- and Ru-doped Nd$$_{1/2}$$A$$_{1/2}$$MnO$$_{3}$$ (A=Ca,Sr)

Kang, J.-S.*; Kim, J. H.*; Sekiyama, Akira*; Kasai, Shuichi*; Suga, Shigemasa*; Han, S. W.*; Kim, K. H.*; Choi, E. J.*; Kimura, Tsuyoshi*; Muro, Takayuki*; et al.

Physical Review B, 68(1), p.012410_1 - 012410_4, 2003/07

A2003-0329.pdf:0.49MB

 Times Cited Count:20 Percentile:68.29(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Prominent quasiparticle peak in the photoemission spectrum of the metallic phase of V$$_{2}$$O$$_{3}$$

Mo, S.-K.*; Denlinger, J. D.*; Kim, H.-D.*; Park, J.-H.*; Allen, J. W.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Kadono, Koji*; Suga, Shigemasa*; Saito, Yuji; et al.

Physical Review Letters, 90(18), p.186403_1 - 186403_4, 2003/05

A2003-0178.pdf:0.18MB

 Times Cited Count:134 Percentile:95.62(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

Helicity switching of circularly polarized undulator radiation by local orbit bumps

Hara, Toru*; Shirasawa, Katsutoshi*; Takeuchi, Masao*; Seike, Takamitsu*; Saito, Yuji; Muro, Takayuki*; Kitamura, Hideo*

Nuclear Instruments and Methods in Physics Research A, 498(1-3), p.496 - 502, 2003/02

 Times Cited Count:56 Percentile:95.51(Instruments & Instrumentation)

no abstracts in English

Journal Articles

Bulk-sensitive photoemission spectroscopy of $$A_{2}$$FeMoO$$_{6}$$ double perovskites ($$A$$=Sr, Ba)

Kang, J.-S.*; Kim, J. H.*; Sekiyama, Akira*; Kasai, Shuichi*; Suga, Shigemasa*; Han, S. W.*; Kim, K. H.*; Muro, Takayuki*; Saito, Yuji; Hwang, C.*; et al.

Physical Review B, 66(11), p.113105_1 - 113105_4, 2002/09

 Times Cited Count:63 Percentile:90.51(Materials Science, Multidisciplinary)

The electronic structures of Sr$$_{2}$$FeMoO$$_{6}$$ (SFMO) and Ba$$_{2}$$FeMoO$$_{6}$$ (BFMO) double perovskites have been investigated using Fe 2p-3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have a strongly mixed Mo–Fe t$$_{2g}$$ character, indicating that the Fe valence is far from pure 3+. The Fe 2p$$_{3/2}$$ x-ray absorption spectroscopy spectra reveal the mixed-valent Fe $$^{3+}$$–Fe$$^{2+}$$ configurations, and a larger Fe$$^{2+}$$ component for BFMO than for SFMO, suggesting an operative double exchange interaction. The valence-band PES spectra reveal good agreement with the local-spin-density-approximation (LSDA+U) calculation.

Journal Articles

High-resolution resonance photoemission study of Ce$$MX$$ ($$M$$=Pt, Pd; $$X$$=P, As, Sb)

Iwasaki, T.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Okazaki, Makoto*; Kadono, Koji*; Utsunomiya, Hiroshi*; Imada, Shin*; Saito, Yuji; Muro, Takayuki*; Matsushita, Tomohiro*; et al.

Physical Review B, 65(19), p.195109_1 - 195109_9, 2002/05

 Times Cited Count:23 Percentile:72.01(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Orbital angular momentum and interpretation of core-absorption magnetic circular dichroism on the band picture in Co-based Heusler alloys Co$$_{2}Y$$Sn ($$Y$$=Ti, Zr, and Nb)

Yamasaki, Atsushi*; Imada, Shin*; Arai, Ryuji*; Utsunomiya, Hiroshi*; Suga, Shigemasa*; Muro, Takayuki*; Saito, Yuji; Kanomata, Takeshi*; Ishida, Shoji*

Physical Review B, 65(10), p.104410_1 - 104410_6, 2002/03

 Times Cited Count:51 Percentile:87.72(Materials Science, Multidisciplinary)

The magnetic circular dichroism (MCD) of core-level absorption [x-ray absorption spectroscopy (XAS)] spectra in the soft x-ray region has been measured for the ferromagnetic Heusler alloys Co$$_{2}$$TiSn, Co$$_{2}$$ZrSn, and Co$$_{2}$$NbSn. The many-peak structures which are clearly observed in the Co 2p-3d XAS-MCD spectra cannot be well explained by atomic multiplet calculations but are better explained by the Co 3d unoccupied states predicted by linear muffin-tin orbital atomic sphere approximation band structure calculations. The MCD spectra show an obvious contribution of the orbital angular momentum component to the magnetic moment in these alloys. The ratio between the orbital angular momentum and spin derived from the MCD spectra varies by more than a factor of 2 within these alloys. The mechanism of this variation is discussed in comparison with the band structure calculations.

Journal Articles

MCD study on materials without magnetic order

Miyahara, Tsuneaki*; Ishii, Hiroyoshi*; Takayama, Yasuhiro*; Hirose, Masaaki*; Maruyama, Kenichi*; Obu, Kenji*; Shinoda, Motoki*; Muro, Takayuki*; Saito, Yuji; Matsuda, Tatsuma*; et al.

Journal of the Physical Society of Japan, 70(10), p.2977 - 2981, 2001/10

 Times Cited Count:5 Percentile:38.89(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

Soft X-ray beamline for spectroscopy of solids at SPring-8

Saito, Yuji; Kimura, Hiroaki*; Suzuki, Yoshio*; Nakatani, Takeshi*; Matsushita, Tomohiro*; Muro, Takayuki*; Miyahara, Tsuneaki*; Fujisawa, M.*; Soda, Kazuo*; Ueda, Shigenori*; et al.

Nuclear Instruments and Methods in Physics Research A, 467-468(Part.1), p.553 - 556, 2001/07

 Times Cited Count:23 Percentile:83.66(Instruments & Instrumentation)

no abstracts in English

45 (Records 1-20 displayed on this page)