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Yomogida, Takumi; Hashimoto, Tadashi; Okumura, Takuma*; Yamada, Shinya*; Tatsuno, Hideyuki*; Noda, Hirofumi*; Hayakawa, Ryota*; Okada, Shinji*; Takatori, Sayuri*; Isobe, Tadaaki*; et al.
Analyst, 149(10), p.2932 - 2941, 2024/03
In this study, we successfully applied a transition-edge sensor (TES) spectrometer as a detector for microbeam X-ray measurements from a synchrotron X-ray light source to determine uranium (U) distribution at the micro-scale and its chemical species in biotite obtained from the U mine. It is difficult to separate the fluorescent X-ray of the U L
line at 13.615 keV from that of the Rb K line at 13.395 keV in the X-ray fluorescence spectrum with an energy resolution of approximately 220 eV of the conventional silicon drift detector (SDD). Meanwhile, the fluorescent X-rays of U L and Rb K were fully separated by TES with 50 eV energy resolution at the energy of around 13 keV. The successful peak separation by TES led to an accurate mapping analysis of trace U in micro-X-ray fluorescence measurements and a decrease in the signal-to-background ratio in micro-X-ray absorption near edge structure spectroscopy.
-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：4 Percentile：29.37(Chemistry, Analytical)no abstracts in English
Pt-NMR study on noncentrosymmetric heavy-fermion superconductor CePt
SiYogi, Mamoru*; Kitaoka, Yoshio*; Hashimoto, Shin*; Yasuda, Takashi*; Settai, Rikio*; Matsuda, Tatsuma; Haga, Yoshinori; Onuki, Yoshichika; Rogl, P.*; Bauer, E.*
Journal of Physics and Chemistry of Solids, 67(1-3), p.522 - 524, 2006/01
Times Cited Count：9 Percentile：41.49(Chemistry, Multidisciplinary)We report on magnetic and novel superconducting properties in heavy-fermion (HF) noncentrosymmetric compound CePtSi via the measurement of Pt nuclear spin-lattice relaxation rate 1/
. This compound reveals the uniform coexistence of antiferromagnetism (
=2.2 K) and superconductivity (
=0.75 K). CePtSi is the first HF superconductor that reveals a peak in 1/ just below and, additionally, does not follow the 
law that was observed for most unconventional HF superconductors. The novel relaxation behavior found below may be relevant with a possible novel SC state being realized in the noncentrosymmetric CePtSi.
Si; 
Si-NMR Knight shift studyYogi, Mamoru*; Mukuda, Hidekazu*; Kitaoka, Yoshio*; Hashimoto, Shin*; Yasuda, Takashi*; Settai, Rikio*; Matsuda, Tatsuma; Haga, Yoshinori; Onuki, Yoshichika; Rogl, P.*; et al.
Journal of the Physical Society of Japan, 75(1), p.013709_1 - 013709_4, 2006/01
Times Cited Count：64 Percentile：88.14(Physics, Multidisciplinary)We report the measurements of the Si Knight shift K
on the noncentrosymmetric heavy-fermion compound CePtSi in which antiferromagnetism (AFM) with 
=2.2 K coexists with superconductivity (SC) with 
=0.75 K. Its spin part K, which is deduced to be K
0.11 and 0.16 at respective magnetic fields H=2.0061 and 0.8671 T,. does not decrease across the superconducting transition temperature Tc for the field along the c-axis. The temperature dependence of nuclear spin-lattice relaxation of Pt below Tc has been accounted for by a Cooper pairing model with a two-component order parameter composed of spin-singlet and spin-triplet pairing components. From this result, it is shown that the Knight-shift data are consistent with the occurrence of the two-component order parameter for CePtSi.
; Toshimitsu Yamazaki*; Hajime Ohnuma*; Yoshio Hashimoto*; Manabu Fujioka*
Journal of the Physical Society of Japan, 17(8), p.1223 - 1229, 1962/00
Times Cited Count：6no abstracts in English
Noda, Yohei; Koizumi, Satoshi; Hashimoto, Takeji; Shimono, Satoshi*; Baba, Masaaki*; Yamauchi, Jun*; Ikuma, Naohiko*; Uchida, Yoshiaki*; Tamura, Rui*; Iima, Yoshio*
no journal, ,
Recently, the chiral paramagnetic liquid crystals (LCs) were synthesized, whose spin sources are fixed in their rigid core. Their responses to an electric and magnetic fields are attractive topics. In general, LC molecules align with the rubbing direction on the oriented film of the LC cell. By far, by use of this surface stabilization effect on LC cell surface, we have developed this potential method of the EPR measurement with rotating the oriented LC cell sample. More recently, the chiral paramagnetic LC showing ferroelectricity was synthesized. We will report the EPR investigation of the orientation change of the ferroelectric LC in response to the switching of an applied electric field. It was shown by the EPR measurement that with no electric field, the LC molecules directed nearly uniformly along the rubbing direction on the cell surface, on the other hand, with electric field (24V), the LC molecules largely tilted from the normal line of the smectic layer.
Yomogida, Takumi; Yamada, Shinya*; Ichinohe, Yuto*; Sato, Toshiki*; Hayakawa, Ryota*; Okada, Shinji*; Toyama, Yuichi*; Hashimoto, Tadashi; Noda, Hirofumi*; Isobe, Tadaaki*; et al.
no journal, ,
Biotite is known as a host phase that retains uranium (U) in uranium deposits at Ningyo-Toge and Tono, and it is expected that the distribution of U in biotite will provide insight into the concentration and long-term immobilization of U. However, biotite contains rubidium (Rb), which interferes with X-ray fluorescence analysis, making it difficult to accurately determine the distribution of U-Rb in biotite by measurement using a conventional solid state detector (SSD). In this study, we developed a method to use a transition edge sensor (TES) as a detector in microbeam X-ray fluorescence analysis, which enables us to detect X-ray fluorescence with an energy resolution of about 20 eV and to obtain a Rb K line at 13.373 keV and a U L line at 13.612 keV can be completely separated. Therefore,the developed method enables us to accurately determine the distribution of U-Rb in biotite.
Yomogida, Takumi; Yamada, Shinya*; Ichinohe, Yuto*; Sato, Toshiki*; Hayakawa, Ryota*; Okada, Shinji*; Toyama, Yuichi*; Hashimoto, Tadashi; Noda, Hirofumi*; Isobe, Tadaaki*; et al.
no journal, ,
The reduction of uranium on biotite was studied to obtain insight into the immobilization of uranium in the environment. The chemical species of uranium in biotite were studied using a superconducting transition edge sensor and an X-ray emission spectrometer to remove interference from rubidium in biotite. As a result, the speciation of uranium in biotite collected from former uranium deposits was possible. The XANES spectra of the biotite indicated that the uranium in the biotite was partially reduced.
