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Metoki, Naoto
Kotai Butsuri, 55(7), p.285 - 296, 2020/07
Electron states are the main theme of "solid-state physics", which is essential for microscopic understanding of multipoles and superconductivity, etc. Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.
Metoki, Naoto; Aczel, A. A.*; Aoki, Dai*; Chi, S.*; Fernandez-Baca, J. A.*; Griveau, J.-C.*; Hagihara, Masato*; Hong, T.*; Haga, Yoshinori; Ikeuchi, Kazuhiko*; et al.
JPS Conference Proceedings (Internet), 30, p.011123_1 - 011123_6, 2020/03
Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.
Metoki, Naoto; Aoki, Dai*; Griveau, J.-C.*; Otsuki, Junya*
Journal of the Physical Society of Japan, 89(2), p.024707_1 - 024707_6, 2020/02
Times Cited Count:3 Percentile:30.12(Physics, Multidisciplinary)The pseudo triplet ground state in the heavy-fermion superconductor NpPdAl was concluded. The magnetic susceptibility can be reproduced by the singlet ground state with the main component of and the first excited doublet dominated by at ,K. The magnetization curve can be explained from the effective local hamiltonian for pseudo spin =1 with () equivalent to the quadrupole operator . The specific heat can be described with the Kondo model normalized to give the entropy R, corresponding to the pseudo triplet state. The derived Kondo temperature ,K comparable to the level splitting ,K indicates the contribution of the excited doublet to the possible multi-channel Kondo effect.
Ideta, Shinichiro*; Murai, Naoki; Nakajima, Masamichi*; Kajimoto, Ryoichi; Tanaka, Kiyohisa*
Physical Review B, 100(23), p.235135_1 - 235135_7, 2019/12
Times Cited Count:3 Percentile:15.75(Materials Science, Multidisciplinary)Teruya, Atsushi*; Takeda, Masataka*; Nakamura, Ai*; Harima, Hisatomo*; Haga, Yoshinori; Uchima, Kiyoharu*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
Journal of the Physical Society of Japan, 84(5), p.054703_1 - 054703_15, 2015/05
Times Cited Count:4 Percentile:34.59(Physics, Multidisciplinary)Kobata, Masaaki; Kobayashi, Keisuke*
Journal of the Vacuum Society of Japan, 58(2), p.43 - 49, 2015/02
We report the applications of a hard X-ray photoelectron spectroscopy to the characterization of SiO/Si(001)systems. Large escape depth of high-energy photoelectron enables us to probe buried layers and their interfaces in multilayer structures. Estimation of SiO overlayer thicknesses up to 25 nm by angle resolved XPS was possible in SiO/Si(001) samples. Determination of the thickness profile of a wedged shape SiO buried layer was successfully done in Ir (8 nm)/HfO (2.2 nm)/thickness graded-SiO (0-10 nm) / Si (100). The Si 1s core level showed a SiO thickness dependent shift, which was ascribed to fixed charge at the SiO-Si interface. Energy distribution of interface states at ultrathin thermal oxide/Si(100) interfaces were determined by Si 1 core level shift by applying gate bias in metal-oxide-semiconductor (MOS) structure with 5 nm Au gate electrodes.
Hirose, Yusuke*; Takeuchi, Tetsuya*; Yoshiuchi, Shingo*; Yamamoto, Etsuji; Haga, Yoshinori; Settai, Rikio*; Onuki, Yoshichika
JPS Conference Proceedings (Internet), 3, p.011056_1 - 011056_6, 2014/06
Iihara, Junji*; Muramatsu, Yasuji; Takebe, Toshihiko*; Sawamura, Akitaka*; Namba, Akihiko*; Imai, Takahiro*; Denlinger, J. D.*; Perera, R. C. C.*
Japanese Journal of Applied Physics, Part 1, 44(9A), p.6612 - 6617, 2005/09
Times Cited Count:12 Percentile:43.14(Physics, Applied)Electronic structure transition between semiconducting and metallic states in boron (B) -doped diamonds was element-selectively observed by soft X-ray emission and absorption spectroscopy using synchrotron radiation. For the lightly B-doped diamonds, the B 2-density of states (DOS) in the valence band were enhanced with a steep-edge-feature near the Fermi level, and localized acceptor levels, characteristic of semiconductors, were clearly observed both in B 2- and C 2-DOS in the conduction bands. For the heavily B-doped diamonds, the localized acceptor levels developed into extended energy levels and new energy levels were generated to form an extended conduction band structure which overlapped with the valence band. Thus, this clarified that the metallic energy band structure is actually formed by heavy boron doping. Such valence and conduction band structures observed by soft X-ray emission and absorption spectroscopy well accounted for the electrical properties of the B-doped diamonds.
Yaita, Tsuyoshi; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro; Shimada, Asako*; Assefa, Z.*; Haire, R. G.*
Physica Scripta, T115, p.302 - 305, 2005/00
The structural parameter and the electronic structure of the complex between cerium and N,N'-dimethyl-N,N'-diphenylpyridine-2,6-carboxyamide(DMDPhPDA) was investigated by XAFS, photo luminescence and excitation spectra. The DMDPhPDA is one of the promising ligands for separation of trivalent actinides from lanthanides. The Ce-K XAFS spectra were measured at BL11XU of SPring-8. The bond distances between the carbonyl oxygens and cerium, and between the pyridyl nitrogen and cerium are 253pm and 264pm, respectively. The bond angle of the plane consisting of the two carbonyl oxygens and nitrogen with cerium was about 180 degree. This complex was a yellow color unique for the DMDPhPDA-lanthanide complexes. The photo absorption peak for the complex was extremely broad, and the peak position was at a higher wavenumber as compared with those for the other lanthanide complexes. The peak in the highest wavenumber of this band may be attributed to the transition between f and d orbitals, which are greatly influenced by the ligand field of the DMDPhPDA. The XANES spectrum of the cerium complex clearly showed that cerium was trivalent.
Fujii, Kentaro
Hoshako, 16(3), p.151 - 158, 2003/05
no abstracts in English
Haketa, Naoki*; Yokoyama, Keiichi; Tanaka, Hiromasa*; Kudo, Hiroshi*
Journal of Molecular Structure; THEOCHEM, 577(1), p.55 - 67, 2002/01
no abstracts in English
Teraoka, Yuden; Yoshigoe, Akitaka
JAERI-Tech 2001-009, 41 Pages, 2001/03
no abstracts in English
Hirata, Masaru; Bastug, T.*; Tachimori, Shoichi; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*
Advances in Quantum Chemistry, Volume 37, p.325 - 333, 2001/00
no abstracts in English
Tejima, Shogo
JNC TN8400 2000-029, 54 Pages, 2000/10
This report describes the study done by the author as a postdoctoral research associate at Japan Nuclear Cycle Development Institute. This report is divided into three parts: construction of a relativistic band calculation formalism based on the density functional theory, using this method, investigation of the electrical properties for ferromagnetic UGe and antiferromagnetic UO. (1)A relativistic band calculation (RBC) method. Band calculations for the s, p, and d electric structure have been developed well in the practical application and theoretical study. But band calculation method treating magnetic 5f electrons as actinide compounds are complicated and needed relativistic approach, so it is behind with the study of the 5f system. In this study we construct the relativistic band calculationformalism valid for magnetic 5f electrons. (2)Electric properties of UGe. The actinide compounds UGe is ferromagnetic, so the theoretical analysis is not well yet. The electric structure and fermi surface of UGe are analyzed using the RBC. The theoretical results show that UGe is heavy electron with the 5f character and are agreement with experimental one. (3)Electric structure of nuclear fuel UO. It is important to understand the mechanism of the thermal conductivity of nuclear fuel as antiferromagnetic UO. The UO band calculation reflecting the thermal properties, into account of relativistic effect, have not done yes. So using the RBC the detailed electric structure of UO are obtained.
Kurihara, Masayoshi*; Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*
Journal of Nuclear Materials, 281(2-3), p.140 - 145, 2000/10
Times Cited Count:3 Percentile:26.39(Materials Science, Multidisciplinary)no abstracts in English
Hirata, Masaru; Bastug, T.; Tachimori, Shoichi
Nihon Genshiryoku Gakkai-Shi, 42(10), p.1104 - 1108, 2000/10
Times Cited Count:1 Percentile:12.05(Nuclear Science & Technology)no abstracts in English
Sekiyama, Akira*; Iwasaki, T.*; Matsuda, K.*; Saito, Yuji; Onuki, Yoshichika*; Suga, Shigemasa*
Nature, 403(6768), p.396 - 398, 2000/01
Times Cited Count:255 Percentile:98.91(Multidisciplinary Sciences)no abstracts in English
Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*; Mukoyama, Takeshi*; ; Tachimori, Shoichi
Journal of Alloys and Compounds, 271-273, p.128 - 132, 1998/00
Times Cited Count:8 Percentile:52.55(Chemistry, Physical)no abstracts in English
Watabe, Hiroshi*; Oguchi, Tamio*
Nihon Keisan Kogakkai Rombunshu, 2(1), p.63 - 65, 1997/05
no abstracts in English
; Oguchi, Tamio*
JAERI-Data/Code 97-009, 30 Pages, 1997/03
no abstracts in English