JOPSS - Search Results

Journal Articles

Initial sintering kinetics of non-stoichiometric CeO $_{2-x}$

Watanabe, Masashi; Seki, Takayuki*

Materials Science & Engineering B, 272, p.115369_1 - 115369_6, 2021/10

https://doi.org/10.1016/j.mseb.2021.115369

Times Cited Count：1 Percentile：7.51(Materials Science, Multidisciplinary)

The effect of oxygen non-stoichiometry on the initial sintering behavior of CeO $_{2}$ was investigated. It was found that the initial sintering of the stoichiometric and hypo-stoichiometric composition was controlled by the grain boundary diffusion. The activation energies of cation diffusion were derived from initial sintering data. Moreover, it is suggested that the cation diffusion was caused by a vacancy mechanism.

Journal Articles

Physical properties of non-stoichiometric (U,Pu)O $_{2}$

Watanabe, Masashi; Matsumoto, Taku; Hirooka, Shun; Morimoto, Kyoichi; Kato, Masato

2018 GIF Symposium Proceedings (Internet), p.315 - 320, 2020/05

Recently, a research group studying at Plutonium Fuel Development Facility (PFDF) in Japan Atomic Energy Agency has systematically measured vast amounts of physical properties in the non-stoichiometric (U, Pu)O $_{2}$ . Lattice parameter, elastic modulus, thermal expansion, oxygen potential, oxygen chemical diffusion coefficient and thermal conductivity were successfully measured as function of Pu content, O/M ratio and temperature, and the effects of Pu content and O/M ratio on their physical properties were evaluated. In this work, those experimental data are reviewed, and latest experimental data set on the non-stoichiometric (U, Pu)O $_{2}$ are presented. The data set would be available in development of a fuel performance code.

Journal Articles

Oxygen chemical diffusion coefficients of (U, Pu)O $_{2-x}$

Watanabe, Masashi; Sunaoshi, Takeo*; Kato, Masato

Defect and Diffusion Forum, 375, p.84 - 90, 2017/05

http://doi.org/10.4028/www.scientific.net/DDF.375.84

The oxygen chemical diffusion coefficient in (U, Pu)O $_{2-x}$ was determined by thermo-gravimetry as functions of the Pu content, oxygen-to-metal ratio and temperature. The surface reaction was considered in the diffusion coefficient determination. The activation energy for the chemical diffusion coefficient was 60 kJ/mol and 65 kJ/mol, respectively, in (U $_{0.8}$ Pu $_{0.2}$ )O $_{2-x}$ and (U $_{0.7}$ Pu $_{0.3}$ )O $_{2-x}$ .

Journal Articles

High-temperature thermophysical property measurements on non-stoichiometric composition of Li $_{2}$ TiO $_{3}$

Hoshino, Tsuyoshi; Kobayashi, Takeshi*; Nashimoto, Makoto*; Kawamura, Hiroshi; Terai, Takayuki*; Yamawaki, Michio*; Takahashi, Yoichi*

Journal of the Ceramic Society of Japan, Supplement, Vol.112, No.1 (CD-ROM), p.S354 - S357, 2004/05

no abstracts in English

Journal Articles

Impact of interfaces on nuclear materials

Yamawaki, Michio*; Yamaguchi, Kenji; Suzuki, Atsushi*

Ionics, 7(4-6), p.339 - 345, 2001/07

https://doi.org/10.1007/BF02373568

Times Cited Count：6 Percentile：37.48(Chemistry, Physical)

no abstracts in English

Journal Articles

Phase relations and crystal chemistry in the ternary UO $_{2}$ -PrO $_{1}$ $_{.}$ $_{5}$ -O $_{2}$ system

; Fujino, Takeo; Tagawa, Hiroaki

Journal of Nuclear Materials, 132, p.192 - 201, 1985/00

https://doi.org/10.1016/0022-3115(85)90414-3

Times Cited Count：21 Percentile：89.53(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

On some factors affecting the nonstoichiometry in U $_{3}$ O $_{8}$

Fujino, Takeo; *;

Journal of Nuclear Materials, 97, p.93 - 103, 1981/00

https://doi.org/10.1016/0022-3115(81)90422-0

Times Cited Count：18 Percentile：87.29(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Anomalous change of the oxidation state of uranium in the phase transformation of cadmium monouranate

*; Fujino, Takeo

Inorg.Nucl.Chem.Lett., 16(2), p.91 - 96, 1980/00

https://doi.org/10.1016/0020-1650(80)80100-0

no abstracts in English

Journal Articles

A Gravimetric method for the determination of oxygen in uranium oxides and ternary uranium oxides by addition of alkaline earth compounds

Fujino, Takeo; Tagawa, Hiroaki; ;

Analytica Chimica Acta, 98(2), p.373 - 383, 1978/02

https://doi.org/10.1016/S0003-2670(01)84067-8

Times Cited Count：3

no abstracts in English

Journal Articles

Diffraction study of U $_{2}$ N $_{3+x}$

Masaki, N.; Tagawa, Hiroaki

Journal of Nuclear Materials, 57(2), p.187 - 192, 1975/01

https://doi.org/10.1016/0022-3115(75)90258-5

Times Cited Count：12

no abstracts in English

Oral presentation

Raman spectra of non-stoichiometric (U $_{1-y}$ Ce $_{y}$ )O $_{2}$ solid solution

Watanabe, Masashi; Kato, Masato; Sunaoshi, Takeo*; Yato, Tadao*; Konashi, Kenji*

no journal, ,

Raman spectroscopy has been widely used to detect the oxygen vacancies and proven to be a very powerful characterization technique. The Raman spectral data of non-stoichiometric actinide oxides are very limited. The purpose of this work was to measure the Raman spectra of a non-stoichiometric (U $_{1-y}$ Ce $_{y}$ )O $_{2}$ solid solution. The Raman spectra of stoichiometric and non-stoichiometric (U $_{1-y}$ Ce $_{y}$ )O $_{2}$ are successfully measured. The T $_{2g}$ peak of non-stoichiometric (U $_{1-y}$ Ce $_{y}$ )O $_{2}$ exhibited the same peak shift behavior as hypo-stoichiometric CeO $_{2}$ .

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Initial sintering kinetics of non-stoichiometric CeO $_{2-x}$

Physical properties of non-stoichiometric (U,Pu)O $_{2}$

Oxygen chemical diffusion coefficients of (U, Pu)O $_{2-x}$

High-temperature thermophysical property measurements on non-stoichiometric composition of Li $_{2}$ TiO $_{3}$

Impact of interfaces on nuclear materials

Phase relations and crystal chemistry in the ternary UO $_{2}$ -PrO $_{1}$ $_{.}$ $_{5}$ -O $_{2}$ system

On some factors affecting the nonstoichiometry in U $_{3}$ O $_{8}$

Anomalous change of the oxidation state of uranium in the phase transformation of cadmium monouranate

A Gravimetric method for the determination of oxygen in uranium oxides and ternary uranium oxides by addition of alkaline earth compounds

Diffraction study of U $_{2}$ N $_{3+x}$

Raman spectra of non-stoichiometric (U $_{1-y}$ Ce $_{y}$ )O $_{2}$ solid solution