Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 29

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

XAFS analysis of ruthenium in simulated iron phosphate radioactive waste glass

Okamoto, Yoshihiro; Kobayashi, Hidekazu; Shiwaku, Hideaki; Sasage, Kenichi; Hatakeyama, Kiyoshi*; Nagai, Takayuki

Journal of Non-Crystalline Solids, 551, p.120393_1 - 120393_8, 2021/01

 Times Cited Count:0 Percentile:100(Materials Science, Ceramics)

The chemical state of ruthenium in simulated iron phosphate radioactive waste glass was investigated by conventional X-ray absorption fine structure (XAFS) and imaging XAFS analyses. The EXAFS analysis suggested that ruthenium was contained as glass phase when content of the waste components was less than 10wt.% in 30 mol%Fe$$_{2}$$O$$_{3}$$-P$$_{2}$$O$$_{5}$$ base glass. In other samples, crystalline RuO$$_{2}$$ was predominant. According to the imaging XAFS analysis, RuO$$_{2}$$ particles in all samples had length smaller than 50$$mu$$m. Aggregations of RuO$$_{2}$$, which are found in nuclear waste borosilicate glass, were not seen in any of the iron phosphate glass samples.

Journal Articles

Structural significance of nickel sites in aluminosilicate glasses

Kado, Rikiya*; Kishi, Tetsuo*; Lelong, G.*; Galoisy, L.*; Matsumura, Daiju; Calas, G.*; Yano, Tetsuji*

Journal of Non-Crystalline Solids, 539, p.120070_1 - 120070_8, 2020/07

 Times Cited Count:0 Percentile:100(Materials Science, Ceramics)

Journal Articles

Local structure of room-temperature superionic Ag-GeSe$$_3$$ glasses

Stellhorn, J. R.*; Hosokawa, Shinya*; Kawakita, Yukinobu; Gies, D.*; Pilgrim, W.-C.*; Hayashi, Koichi*; Oyama, Kenji*; Blanc, N.*; Boudet, N.*

Journal of Non-Crystalline Solids, 431, p.68 - 71, 2016/01

 Times Cited Count:6 Percentile:57.29(Materials Science, Ceramics)

Journal Articles

Reversible changes in temperature dependence of electric conductivity of hydrogenated amorphous silicon caused by proton irradiation

Sato, Shinichiro; Oshima, Takeshi

Journal of Non-Crystalline Solids, 392-393, p.11 - 18, 2014/06

We investigate temperature dependence of electric conductivity and photoconductivity of hydrogenated amorphous silicon (a-Si:H) thin films due to energetic proton irradiation and clarify the change in dominant electric conduction mechanism. The results show that the high fluence proton irradiation changes the dominant electric conduction mechanism from the band transport of thermally excited carriers through the extended states to the hopping transport based on the carrier transport via localized states near the Fermi level. The hopping conduction has the weak temperature dependence which disappears at elevated temperature and the strong temperature dependence based on the band conduction appears again. We conclude that the change in dominant electric conduction mechanism is caused by the increase in localized density of states.

Journal Articles

Temporal electric conductivity variations of hydrogenated amorphous silicon due to high energy protons

Sato, Shinichiro; Sai, Hitoshi*; Oshima, Takeshi; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Kondo, Michio*

Journal of Non-Crystalline Solids, 358(17), p.2039 - 2043, 2012/09

 Times Cited Count:5 Percentile:64.5(Materials Science, Ceramics)

Electrical conductivity variations of undoped, n-type and p-type hydrogenated amorphous silicon (a-Si:H) thin films irradiated with various energy protons are systematically investigated in this study. Dark conductivity (DC) and photoconductivity (PC) of the undoped samples increased at first due to proton irradiation and then decrease dramatically with increasing proton fluence. However, increased PC was metastable and gradually decreased with time. Similar results were observed in the n-type a-Si:H, whereas the monotonic decrease was observed in the p-type one. The degrees of the DC and the PC decreases became lower as the irradiated proton energy was higher. The increases of both DC and PC are attributed to the temporal donor like center generation, although the additional proton irradiation decrease both the DC and PC by the accumulation of radiation-induced defects, which are act as deep traps and compensate carriers.

Journal Articles

Proton-induced photoconductivity increment and the thermal stability of a-Si:H thin film

Sato, Shinichiro; Sai, Hitoshi*; Oshima, Takeshi; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Kondo, Michio*

Journal of Non-Crystalline Solids, 356(41-42), p.2114 - 2119, 2010/09

 Times Cited Count:13 Percentile:37.45(Materials Science, Ceramics)

Photoconductivity (PC) variations of device-grade a-Si:H thin films due to proton irradiation are investigated in this paper. We performed in-situ measurements of the PC variations induced by 0.10, 1.0 and 10 MeV proton irradiations. The irradiation initially caused an increase in PC in all sample. However, continued irradiation resulted in a dramatic decrease as the irradiation fluence increased. The results obtained in this study suggest that the PC increment is caused not by accumulation of displacement damage. The results of the temperature dependence of PC for a-Si:H before and after 10 MeV proton irradiation showed that such a proton-induced PC increment consisted of two components: one thermally stable and one metastable. The thermally metastable component disappeared in the temperature region of 300 to 340 K. On the contrary, radiation-induced defects were annealed above 340 K.

Journal Articles

Estimation of inter-atomic force constants and phonon dispersion using correlation effects among thermal displacement of atoms in Ge

Sakuma, Takashi*; Mohapatra, S. R.*; Isozaki, Nobuhiro*; Uehara, Hiroyuki*; Xianglian*; Basar, K.*; Takahashi, Haruyuki*; Kamishima, Osamu*; Igawa, Naoki

Journal of Non-Crystalline Solids, 357(2), p.559 - 562, 2010/01

 Times Cited Count:2 Percentile:81.43(Materials Science, Ceramics)

The oscillatory diffuse scattering intensity of Ge was observed by neutron scattering measurement. The force constants among the first, second and third nearest neighboring atoms in Ge were determined from the values of correlation effects and Debye-Waller temperature parameters. The inter-atomic force constants among the first, second and third nearest neighboring atoms at 80 K in Ge are 363 eV/nm$$^{2}$$, 232 eV/nm$$^{2}$$ and 200 eV/nm$$^{2}$$, respectively.

Journal Articles

High-temperature XAFS study of solid and molten SrCl$$_2$$

Okamoto, Yoshihiro; Yaita, Tsuyoshi; Minato, Kazuo

Journal of Non-Crystalline Solids, 333(2), p.182 - 186, 2004/02

 Times Cited Count:7 Percentile:38.94(Materials Science, Ceramics)

The local structure of solid and molten SrCl$$_2$$ was investigated by X-ray absorption fine structure(XAFS) technique. A superionic conduction state was observed below the melting point. The XAFS data at molten state was obtained at 1000$$^{circ}$$C. According to the curve fitting analysis, the nearest Sr$$^{2+}$$-Cl$$^-$$ distance and the coordination number are 2.99${AA }$ and 6.6 in molten state. XAFS functions calculated from molecular dynamics simulation results were copmpared with the experimental XAFS data.

Journal Articles

The Spectrum and laser properties of ytterbium doped phosphate glass at low temperature

Dai, S.*; Sugiyama, Akira; Hu, L.*; Liu, Z.*; Huang, G.*; Jiang, Z.*

Journal of Non-Crystalline Solids, 311(2), p.138 - 144, 2002/11

Low-temperature absorption and fluorescence spectra of the Yb3+ ions were measured in phosphate glass with compositions of (60-65)P$$_{2}$$O$$_{5}$$-(4-8)B$$_{2}$$O$$_{3}$$-(5-10)Al$$_{2}$$O$$_{3}$$-(10-15)K$$_{2}$$O-(5-10)BaO-(0-2)La$$_{2}$$O$$_{3}$$-(0-2)Nb$$_{2}$$O$$_{5}$$-(4-87)Yb$$_{2}$$O$$_{3}$$ in mol-%. Temperature dependence of lifetime from $$^{2}$$F$$_{5/2}$$ upper level of YB$$^{3+}$$ was investigated with a cryostat. The glass laser performance pumped by 940 nm laser diode was measured at different temperature range. At 8 K, glass laser oscillation had a slope efficiency of 4% and a maximum power of 2 mW at the peak laser wavelength of 1001 nm.

Journal Articles

XAFS study of molten zinc dibromide

Okamoto, Yoshihiro; Fukushima, Kazuko*; Iwadate, Yasuhiko*

Journal of Non-Crystalline Solids, 312(314), p.450 - 453, 2002/10

Local structure of molten ZnBr$$_2$$ was investigated by both of the Zn and the Br XAFS(X-ray absorption fine structure) measurements above their K-absorption edge at 723K. The nearest Zn$$^{2+}$$-Br$$^-$$ distance was determined to be 2.46$AA  for the Zn XAFS and 2.45AA for the Br XAFS.  The coordination number of Br$^-$$ ion around Zn$$^{2+}$$ was about 4. On the other hand, that of Zn$$^{2+}$$ ion around Br$$^-$$ was about 2. The 1st Br$$^-$$-Br$$^-$$ distance was estimated to be 3.9$AA.  They shows that a tetrahedral coordinate (ZnBr$_4$$)$$^{2-}$$ exists and most of the coordinate connects with the next ones through Br$$^-$$ ion. The two XAFS functions in the molten ZnBr$$_2$$ were reproduced by the combination of the molecular dynamics(MD) simulation and the FEFF7 computations.

Journal Articles

In situ observation of a first-order liquid-liquid transition in phosphorus

Katayama, Yoshinori

Journal of Non-Crystalline Solids, 312-314, p.8 - 14, 2002/10

 Times Cited Count:27 Percentile:15.66(Materials Science, Ceramics)

Recently, we have found a sharp pressure-induced structural change between two characteristic structures of liquid phosphorus by an in-situ high-temperature high-presusre x-ray diffraction method using a JAERI beamline, BL14B1, at SPring-8. Our observations --- existence of molecular and polymeric liquids, sharp and reversible change between them and coexistence of two structures during the change --- strongly support that the structural change is a first-order liquid-liquid phase transition. It has been confirmed that the two liquid phases have different densities by a determination of melting curve by x-ray diffraction and by a density measurement by means of x-ray absorption. The structure of liquid P under high pressure resembles that of liquid arsenic.

Journal Articles

Nuclear resonant inelastic scattering of synchrotron radiation by icosahedral quasicrystal i-Al$$_{62}$$Cu$$_{25.5}$$Fe$$_{12.5}$$ and tetragonal crystal $$omega$$-Al$$_{70}$$Cu$$_{20}$$Fe$$_{10}$$

Suzuya, Kentaro; Shibata, Kaoru*; Seto, Makoto*; Kitao, Shinji*; Yoda, Yoshitaka*; Kashihara, Yasuharu*; Tsai, A.*

Journal of Non-Crystalline Solids, 312-314, p.508 - 512, 2002/10

 Times Cited Count:2 Percentile:67.94(Materials Science, Ceramics)

no abstracts in English

Journal Articles

The Structures of alkylimidazolium fluorohydrogenate molten salts studied by high-energy X-ray diffraction

Hagiwara, Rika*; Matsumoto, Kazuhiko*; Tsuda, Tetsuya*; Ito, Yasuhiko*; Kohara, Shinji*; Suzuya, Kentaro; Matsumoto, Hajime*; Miyazaki, Yoshinori*

Journal of Non-Crystalline Solids, 312-314, p.414 - 418, 2002/10

 Times Cited Count:32 Percentile:12.42(Materials Science, Ceramics)

The structures of a series of XF$$^{.}$$2.3HF (X= 1-methylimidazolium (MI), 1-ethyl-3-methylimidazolium (EMI), 1-butyl-3-methylimidazolium (BMI), 1-hexyl-3-methyl-imidazolium (HMI)) room temperature molten salts have been investigated by high-energy synchrotron X-ray diffraction technique. The correlation peaks appeared in the total correlation function are mainly ascribed to intra-molecular correlation of alkylimidazolium cations. However, it is suggested that the peak at around 3.6 $$AA$$ is ascribed not only to intra-molecular but also inter-molecular correlation of the cation. The contribution of the latter is also supported by the first sharp diffraction peak of the total structure factor found at almost the same position as that of a Bragg peak in the simulated X-ray diffraction pattern of solid EMIF$$^{.}$$HF with a layered structure, corresponding to the layer separation of

Journal Articles

X-ray diffraction measurements for expanded fluid Se using synchrotron radiation up to the dense vapor region

Inui, Masanori*; Hong, X.*; Matsusaka, Tetsuya*; Ishikawa, Daisuke*; Kazi, M. H.*; Tamura, Kozaburo*; Funakoshi, Kenichi*; Utsumi, Wataru

Journal of Non-Crystalline Solids, 312-314, p.274 - 278, 2002/10

 Times Cited Count:2 Percentile:67.94(Materials Science, Ceramics)

no abstracts in English

Journal Articles

High-energy X-ray diffraction studies of non-crystalline materials

Ono, Hideo; Kohara, Shinji*; Umesaki, Norimasa*; Suzuya, Kentaro

Journal of Non-Crystalline Solids, 293-295, p.125 - 135, 2001/11

no abstracts in English

Journal Articles

High-energy X-ray diffraction studies of non-crystalline materials

Ono, Hideo; Kohara, Shinji*; Umesaki, Norimasa*; Suzuya, Kentaro

Journal of Non-Crystalline Solids, 293-295, p.125 - 135, 2001/11

 Times Cited Count:22 Percentile:28.43(Materials Science, Ceramics)

no abstracts in English

Journal Articles

$$^{31}$$P NMR study of magnesium phosphate glasses

Fayon, F.*; Massiot, D.*; Suzuya, Kentaro; Price, D. L.*

Journal of Non-Crystalline Solids, 283(1-3), p.88 - 94, 2001/05

 Times Cited Count:49 Percentile:11.06(Materials Science, Ceramics)

no abstracts in English

Journal Articles

Structural studies of expanded fluid mercury using synchrotron radiation

Tamura, Kozaburo*; Inui, Masanori*; Nakaso, Ichiro*; Oishi, Yasufumi*; Funakoshi, Kenichi*; Utsumi, Wataru

Journal of Non-Crystalline Solids, 250-252(Part1), p.148 - 153, 1999/08

no abstracts in English

Journal Articles

X-ray diffraction measurements for expanded fluid-Se using synchrotron radiation

Inui, Masanori*; Tamura, Kozaburo*; Oishi, Yasufumi*; Nakaso, Ichiro*; Funakoshi, Kenichi*; Utsumi, Wataru

Journal of Non-Crystalline Solids, 250-252(Part2), p.519 - 524, 1999/08

no abstracts in English

Journal Articles

EXAFS study on liquid selenium and liquid tellurium under high pressure

Katayama, Yoshinori; Shimomura, Osamu; Tsuji, Kazuhiko*

Journal of Non-Crystalline Solids, 250-252(Part2), p.537 - 541, 1999/08

no abstracts in English

29 (Records 1-20 displayed on this page)