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Yoneda, Yasuhiro
JSAP Review (Internet), 2023, p.230202_1 - 230202_7, 2023/00
It is important to determine whether a sample is a single phase or not in order to improve the quality of ferroelectrics. Therefore, we have succeeded in developing a detection method for trace amounts of segregated phases by using two-body correlation distribution function (PDF) in addition to X-ray diffraction, which has been conventionally used to detect impurities. In the X-ray diffraction pattern of the BaTiO
-BiFeO solid solution, it appears as a single phase with a rhombohedral structure. However, when the PDF was calculated from the obtained diffraction pattern, it was found that not only the component derived from the rhombohedral crystal structure calculated from the average structure but also the BaTiO component was mixed and segregated. By using PDF in this way, it has become possible to detect fine segregation phases on the order of nanoscale.
Ogawa, Shuichi*; Tsuda, Yasutaka; Sakamoto, Tetsuya*; Okigawa, Yuki*; Masuzawa, Tomoaki*; Yoshigoe, Akitaka; Abukawa, Tadashi*; Yamada, Takatoshi*
Applied Surface Science, 605, p.154748_1 - 154748_6, 2022/12
Times Cited Count：3 Percentile：48.5(Chemistry, Physical)Immersion of graphene in KOH solution improves its mobility on SiO
/Si wafers. This is thought to be due to electron doping by modification with K atoms, but the K atom concentration C
in the graphene has not been clarified yet. In this study, the C was determined by XPS analysis using high-brilliance synchrotron radiation. The time evolution of C was determined by real-time observation, and the C before irradiation of synchrotron radiation was estimated to be 0.94%. The C 1s spectrum shifted to the low binding energy side with the desorption of K atoms. This indicates that the electron doping concentration into graphene is decreasing, and it is experimentally confirmed that K atoms inject electrons into graphene.
Yoneda, Yasuhiro
Oyo Butsuri, 91(12), p.729 - 735, 2022/12
It is important to determine whether a sample is a single phase or not in order to improve the quality of ferroelectrics. Therefore, we have succeeded in developing a detection method for trace amounts of segregated phases by using two-body correlation distribution function (PDF) in addition to X-ray diffraction, which has been conventionally used to detect impurities. In the X-ray diffraction pattern of the BaTiO-BiFeO solid solution, it appears as a single phase with a rhombohedral structure. However, when the PDF was calculated from the obtained diffraction pattern, it was found that not only the component derived from the rhombohedral crystal structure calculated from the average structure but also the BaTiO component was mixed and segregated. By using PDF in this way, it has become possible to detect fine segregation phases on the order of nanoscale.
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki
Journal of Radioanalytical and Nuclear Chemistry, 309(1), p.303 - 308, 2016/07
Times Cited Count：2 Percentile：19.71(Chemistry, Analytical)The technique of sequential separation for U, Th, Pb, lanthanides and Pu using a single anion-exchange column and mixed acids media were developed. An automatic system utilizing a small column and pressurized gas was assembled for this sequential separation. By adjusting the eluent chemical composition for Pu separation, this separation technique has been achieved. Some pieces of tree ring sample were digested, and ultra-trace U and Pu in the samples were separated by this system. The analytical results of U and Pu measured by mass spectrometry will be mentioned.
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki
KEK Proceedings 2015-4, p.44 - 48, 2015/11
We developed an automatic system for sequential separation with an anion-exchange column to simply and quickly separate less than pico-grams of ultra-trace U, Th, Pb, the lanthanide, and Pu in an environmental sample without foreign contamination. The objective sequential separation of ultra-trace multi-elements succeeded by choosing the HCl-HF mixture based acetic acid for Th separation and the HCl-diluted HF mixture for Pu separation. The objective elements in a multi-elements mixture were completely separated for 6 h 15 min by use of the automatic system and the optimized separation condition.
Miyamoto, Yutaka; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki
Analytical and Bioanalytical Chemistry, 407(23), p.7165 - 7173, 2015/09
Times Cited Count：8 Percentile：31.37(Biochemical Research Methods)Age of individual uranium-plutonium mixed particles with various U/Pu atomic ratios were determined by inductively-coupled plasma mass spectrometry. Micron-sized particles were prepared from U and Pu certified reference materials. The Pu reference was stored for 4-6 years since the last purification. The Pu purification age was obtained from the 
Am/Pu ratio which was calculated from the product of three measured ratios of Pu and Am isotopes in the eluted fractions. Am, U and Pu in a sample solution were sequentially separated a small anion-exchange column. The Am/Pu ratio was accurately determined by spiking pure 
Am to the sample solution. The determined age of particles with various U/Pu ratios was in good agreement with the expected age with high accuracy and high precision.
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki
Analyst, 140(13), p.4482 - 4488, 2015/07
Times Cited Count：6 Percentile：21.67(Chemistry, Analytical)Uranium, Thorium, lead, and the lanthanides were automatically and sequentially separated with a single anion-exchange column. This separation was achieved using eluents consisting of simple and highly pure acid mixture of HCl, HNO, acetic acid, and HF. This simple, automatic system is driven with pressurized nitrogen gas, and controlled by a computer program. For an evaluation examination, a reference powdered rock sample was separated by using this system. Abundances of objective elements, including 0.23 ng of lutetium, were accurately determined without corrections of chemical recovery yield or subtraction of processing blank. This separation technique saves time and effort for chemical processing, and it is useful for ultra-trace quantitative and isotopic analyses of elements in small environmental samples.
Magara, Masaaki
Kaku Busshitsu Kanri Senta Nyusu, 34(11), P. 18, 2005/11
no abstracts in English
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Dai-26-Kai Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Nenji Taikai Rombunshu, p.157 - 164, 2005/00
JAERI has conducted the analysis of domestic and the IAEA samples. JAERI is developing the analytical techniques to improve the analytical ability for the safeguards environmental samples. For bulk analysis, study is focused on the improvement of reliability of isotope ratio measurements by ICP-MS. New chemical separation techniques are under development and a desolvation module is introduced to reduce the polyatomic interferences. In particle analysis, the sample preparation procedure for SIMS method is modified to measure the 
U/
U and 
U/U ratios for individual particles. We are also developing fission track-TIMS method to measure uranium isotope ratios in particles of sub-micrometer size. A screening instrument of X-ray fluorescent analysis is equipped to measure elemental distribution on a swipe surface.
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of INMM 46th Annual Meeting (CD-ROM), 8 Pages, 2005/00
JAERI has been developing analytical techniques for ultra-trace amounts of nuclear materials in the environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis of the environmental swipe sample has been established as an ultra-trace analytical method of uranium and plutonium. In January 2003, JAERI was qualified as a member of the IAEA network analytical laboratories for environmental samples. Since then, JAERI has conducted the analysis of domestic and the IAEA samples. From Japanese fiscal year 2003, the second phase of the project was started for the development of advanced techniques, such as analyzing minor actinides and fission products as well as uranium and plutonium, particle analysis using fission-track technique, more efficient particle analysis using ICP-TOFMS and screening by X-ray fluorescent analysis. This paper deals with the progress in the development of the new techniques, applications and future perspective.
Usuda, Shigekazu
Kagaku To Kyoiku, 51(10), p.612 - 613, 2003/10
no abstracts in English
Usuda, Shigekazu
Kaku Busshitsu Kanri Senta Nyusu, 32(7), p.10 - 11, 2003/07
no abstracts in English
Hanzawa, Yukiko; Magara, Masaaki; Watanabe, Kazuo; Esaka, Fumitaka; Miyamoto, Yutaka; Yasuda, Kenichiro; Gunji, Katsubumi*; Sakurai, Satoshi; Takano, Seinojo*; Usuda, Shigekazu; et al.
Journal of Nuclear Science and Technology, 40(1), p.49 - 56, 2003/01
Times Cited Count：4 Percentile：31.64(Nuclear Science & Technology)The JAERI has established a cleanroom facility with cleanliness of ISO Class 5: the Clean Laboratory for Environmental Analysis and Research (CLEAR). It was designed to be used for the analysis of nuclear materials in environmental samples for the safeguards, the Comprehensive Nuclear-Test-Ban Treaty verification and research on environmental sciences. The CLEAR facility was designed to meet double conflicting requirements of a cleanroom and for handling of nuclear materials according to Japanese regulations, i.e., to avoid contamination from outside and to contain nuclear materials inside the facility. This facility has been intended to be used for wet chemical treatment, instrumental analysis and particle handling. A fume-hood to provide a clean work surface for handling of nuclear materials was specially designed. The performance of the cleanroom and analytical background in the laboratory are discussed. It can be concluded that the CLEAR facility enables analysis of ultra trace amounts of nuclear materials at the sub-picogram level in environmental samples.
Hatsukawa, Yuichi; Toh, Yosuke; Oshima, Masumi; Hayakawa, Takehito; Shinohara, Nobuo; Kushita, Kohei; Ueno, Takashi; Toyoda, Kazuhiro*
Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.111 - 113, 2003/01
Times Cited Count：12 Percentile：62.23(Chemistry, Analytical)no abstracts in English
- and X-ray measurements by means of Compton suppression technique for safeguards environmental samplesYasuda, Kenichiro; Mori, Masahito*; Miyamoto, Yutaka; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu
Journal of Nuclear Science and Technology, 39(Suppl.3), p.576 - 578, 2002/11
no abstracts in English
Magara, Masaaki; Sakakibara, Takaaki; Kurosawa, Setsumi; Takahashi, Masato; Sakurai, Satoshi; Hanzawa, Yukiko; Esaka, Fumitaka; Watanabe, Kazuo; Usuda, Shigekazu
Journal of Analytical Atomic Spectrometry, 17(9), p.1157 - 1160, 2002/09
Times Cited Count：11 Percentile：44.18(Chemistry, Analytical)no abstracts in English
Miyabe, Masabumi; Geppert, C.*; Oba, Masaki; Wakaida, Ikuo; Wendt, K.*
Journal of Physics B; Atomic, Molecular and Optical Physics, 35(18), p.3865 - 3877, 2002/09
Times Cited Count：12 Percentile：50.16(Optics)no abstracts in English
Hatsukawa, Yuichi; Oshima, Masumi; Hayakawa, Takehito; Toh, Yosuke; Shinohara, Nobuo
Nuclear Instruments and Methods in Physics Research A, 482(1-2), p.328 - 333, 2002/04
Times Cited Count：25 Percentile：81.52(Instruments & Instrumentation)no abstracts in English
Sakurai, Satoshi; Hanzawa, Yukiko; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Adachi, Takeo
Kuki Seijo, 39(6), p.404 - 410, 2002/03
no abstracts in English
Miyamoto, Yutaka; Oda, Tetsuzo; Adachi, Takeo; Noguchi, Hiroshi; Nishimura, Hideo; Usuda, Shigekazu
Nukleonika, 46(4), p.123 - 126, 2001/12
no abstracts in English
