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-electron states in UPd
Al
Metoki, Naoto; Haga, Yoshinori; Yamamoto, Etsuji; Matsuda, Masaaki*
no journal, ,
We observed clear crystal field excitations of UPdAl, indicating the localized character of 5f electrons with the singlet ground state of U
(5). The excitation spectra and susceptibility can be explained with a similar level scheme of PrPdAl with 10 times larger energy scale due to a larger itinerancy of 5
electrons. The valence (5 electron number) rapidly changes from U to Np
. This valence change may play important role for the heavy fermion superconductivity in NpPdAl.
-electron states in RPdAl (R: Pr, Nd)Metoki, Naoto; Yamauchi, Hiroki; Kitazawa, Hideaki*; Suzuki, Hiroyuki*; Hagihara, Masato*; Masuda, Takatsugu*; Matsuda, Masaaki*; Aczel, A. A.*; Songxue, C.*; Hong, T.*; et al.
no journal, ,
In order to elucidate the 5-electron states in the heavy electron superconductor NpPdAl, neutron scattering experiments of the rare earth based iso-structural family have been carried out. The observed crystal field excitations of PrPdAl and NdPdAl were analyzed via the crystal field Hamiltonian with tetragonal symmetry, diagonalized analytically. The experimentally obtained crystal field parameters 
were very similar in CePdAl, PrPdAl, and NdPdAl, indicating a common effective charge potential in this series. We succeeded to clarify the 5 electron states of NpPdAl and UPdAl in comparison with these results.
-electron states in NpPdAl and the origin of the heavy fermion stateMetoki, Naoto; Aoki, Dai*; Griveau, J.-C.*; Otsuki, Junya*
no journal, ,
Non-Krammers trivalent Np(5
) ion in the heavy fermion superconductor NpPdAl shows 
=4, similar to Pr. We determined the singlet ground state of 
and the first excited doublet of 
above 49 K from the quantitative analysis of the magnetic susceptibility and the magnetization curve. The must contribute to the heavy fermion, since the singlet ground state alone cannot, where 2-channel Kondo effect appears based on . The low-temperature specific heat of NpPdAl can be explained with the superposition of the heavy fermion state and localized Schottky anomaly, where the total entropy was maintained 
ln3 for pseudo-triplet state. The 
-coupling scheme of AnPdAl can be described by the corresponding 
- coupling scheme, where Pu and Np are the hole version of Ce and Pr. The in NpPdAl is stabilized with the same mechanism as in PrTX
, both exhibit the unconventional superconductivity.
studied by photoelectron spectroscopyFujimori, Shinichi; Kawasaki, Ikuto; Takeda, Yukiharu; Yamagami, Hiroshi; Nakamura, Ai*; Homma, Yoshiya*; Aoki, Dai*
no journal, ,
no abstracts in English
Matsubara, Akihiro; Fujita, Natsuko; Kimura, Kenji
no journal, ,
no abstracts in English
Kai, Takeshi; Ishida, Akira*; Oshima, Nagayasu*
no journal, ,
When a positron was injected into the condensed phase, positronium (Ps) which constructs of an electron and a positron was generated. Although we expect that Bose-Einstein condensation (BEC) using the densely positroniums creates newly physics such as gravity accurate measurement of antimatter and annihilation gamma-rays laser, the BEC have never been achieved. The aims of this study are that fundamental explication of Ps generation as well as elucidation of experimental condition for Ps - BEC achievement from the positrons deceleration simulation in the condensed phase. For the aims, we applied a dynamic Monte Carlo code of the electrons to deceleration simulation of positrons bunch. We present current states of development of the high dense positrons transport simulation in the condensed phase.
Yokota, Terufumi
no journal, ,
no abstracts in English
Yamaguchi, Atsushi*; Muramatsu, Haruka*; Hayashi, Tasuku*; Mitsuda, Kazuhisa*; Yuasa, Naoki*; Maehata, Keisuke*; Nakamura, Keisuke; Takimoto, Misaki; Kikunaga, Hidetoshi*
no journal, ,
no abstracts in English
Fe
O
Kobata, Masaaki; Yoshii, Kenji; Fukuda, Tatsuo; Kawasaki, Ikuto; Okane, Tetsuo; Yamagami, Hiroshi; Yaita, Tsuyoshi; Harii, Kazuya; Ieda, Junichi; Okayasu, Satoru; et al.
no journal, ,
We have conducted high energy X-ray photoelectron spectroscopy (HAXPES) measurements on spin Seebeck system Pt/YFeO(YIG) using synchrotron radiation at BL22XU of SPring-8. It was found that the Fe ions are partially converted to a metallic Fe
state, a finding being consistent with the proposed mechanism of characteristic behavior such as anomalous Hall effect. We have also observed that two or more valence states of Fe ions in samples with low electric power generations, showing an inhomogeneous nature of the system. The other spectra such as O 1s and Pt 4f will be presented at the conference,
MeSb[Pd(dmit)] studied by 
SRKawamura, Seiko; Guerin, L.*; Watanabe, Isao*; Kato, Reizo*
no journal, ,
Anion radical salt 
[Pd(dmit)] ( is a counter cation) has a two-dimensional isotropic/distorted triangular lattice structure formed by Pd(dmit) dimers. Spin-1/2 is localized at each dimer in an insulating phase. One of them, EtMeSb[Pd(dmit)], has been suggested to exhibit an isotropic triangular lattice structure and to occur a first-order transition to charge separation accompanying with formation of spin-singlet state at 
= 70 K. We have obtained the evidence for the appearance of the spin-singlet state from previous muon spin relaxation (SR) measurements on this system. However, the temperature at which the muon spin relaxation rate shows an anomaly was slightly different from suggested one. Recently, a high-resolution X-ray structure analysis reported that this system exhibits an incommensurate structure phase below 
= 105 K and a commensurate charge separation phase below 
= 66.5 K. We performed additional SR study, and observed a slight increase in dynamical component below and an obvious enhancement of the dynamical fluctuation below .
Te-NMR study of magnetic fluctuations in a newly discovered uranium-based superconductor UTeTokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Hattori, Taisuke; Higa, Nonoka*; Nakamine, Genki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Nakamura, Ai*; Shimizu, Yusei*; et al.
no journal, ,
Te NMR studies have been performed on a newly discovered heavy fermion superconductor UTe.Using a single crystal, we have measured the Te NMR Knight shift 
and spin-lattice relaxation rate 
for fields along the three orthorhombic crystal axes. The data confirm a moderate Ising anisotropy for both the static () and dynamical susceptibilities () in the paramagnetic state above about 20 K. Around 20 K, however, we have observed a sudden loss of NMR spin-echo signal due to sudden enhancement of the NMR spin-spin relaxation rate 
, when the field is applied along the easy axis of magnetization (=
axis).
RhSi using magnetic pair distribution functionKodama, Katsuaki; Honda, Takashi*; Yamauchi, Hiroki; Shamoto, Shinichi; Ikeda, Kazutaka*; Otomo, Toshiya*
no journal, ,
no abstracts in English
Al
Kambe, Shinsaku; Sakai, Hironori; Tokunaga, Yo; Haga, Yoshinori; Masuda, Hayato*; Higashinaka, Ryuji*; Matsuda, Tatsuma*; Aoki, Yuji*
no journal, ,
no abstracts in English
FeO under ultrasound irradiationShamoto, Shinichi; Akatsu, Mitsuhiro*; Matsuura, Masato*; Ieda, Junichi; Yasui, Yukio*; Harii, Kazuya; Ono, Masao; Yamamoto, Kei; Ito, Takashi; Nemoto, Yuichi*
no journal, ,
no abstracts in English
Si and UCuGe using soft X-ray circular magnetic dichroismTakeda, Yukiharu; Yamagami, Hiroshi; Homma, Yoshiya*; Aoki, Dai*; Iha, Wataru*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
no journal, ,
no abstracts in English
Ieda, Junichi; Yamamoto, Kei
no journal, ,
no abstracts in English
systemsKambe, Shinsaku
no journal, ,
no abstracts in English
GaO showing thermal Hall effectMori, Michiyasu; Fujita, Masaki*; Nambu, Yusuke*; Kawamura, Seiko; Kofu, Maiko; Nakajima, Kenji; Urlich, C.*; Sushkov, O. P.*
no journal, ,
no abstracts in English
S NMR study in 
-USSakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Ramakrishna, S. K.*; Reyes, A. P.*; Rosa, P. F. S.*; Ronning, F.*; Thompson, J. D.*; Bauer, E. D.*
no journal, ,
Uranium disulfide -US is a paramagnetic semiconductor with a narrow band gap of 90 K at low temperatures, whereas above 80 K it is a semimetal with an extremely low density of carriers. Another characteristic feature in -US is the strong response of the electrical resistivity to magnetic field. The magnetoresistance is similar to that of colossal magnetoresistance materials but very anisotropic. In order to clarify the microscopic spin dynamics in -US, nuclear magnetic resonance experiments have been performed. Since the natural concentration of S nuclei (
) is only 0.76%, isotopic enrichment to 50% has been carried out. In the presentation, we would like to discuss about the microscopic magnetism in -US to show the NMR results under high fields.
mimFeClKofu, Maiko; Watanuki, Ryuta*; Sakakibara, Toshiro*; Kawamura, Seiko; Nakajima, Kenji; Ueki, Takeshi*; Akutsu, Kazuhiro*; Yamamuro, Osamu*
no journal, ,
no abstracts in English