المؤلفون: Chinkhai Ong, Wengnam Lee, Linghong Lim, Wuyi Chong, Jingwen Chew, Yasuhiko Hayashi, Takeshi Nishikawa, Patrik Öhberg, Harith Ahmad, Yuenkiat Yap

المصدر: Japanese Journal of Applied Physics. 62:035002

مصطلحات موضوعية: General Engineering, General Physics and Astronomy

الوصف: Dispersion stability of tin(IV) oxide nanoparticles dispersed in N-Methy-2-Pyrrolidone (NMP), dimethylformamide (DMF) and distilled water assisted by ultrasonication was investigated, aiming to identify a suitable liquid medium to effectively disperse tin(IV) oxide for many useful applications. The dispersions’ stability was characterized using field emission scanning electron microscopy, ultraviolet–visible spectroscopy and Zeta potential. The results show that distilled water has the highest stability with optimum sonication of 1 h. NMP shows better stability and consistency than DMF at different sonication timings. Good agreement between ultraviolet–visible absorbance and Zeta potentials shows that both distilled water and NMP are good mediums to produce highly stable tin(V) oxide dispersion.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::00d3f42ffe756003efa9d175e36e00b6Test
https://doi.org/10.35848/1347-4065/acc0b5Test

المؤلفون: Tomoya Miyake, Masaki Hada, Yoichi Hasegawa, Ryota Nagaoka, Takeshi Nishikawa, Hiromi Ota, Yasuhiko Hayashi, Yoshifumi Yamashita, Ulugbek Abdullaev

المصدر: Japanese Journal of Applied Physics. 57:028001

مصطلحات موضوعية: Diffraction, Materials science, Physics and Astronomy (miscellaneous), General Engineering, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Crystal structure, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Crystal, X-ray crystallography, Molecule, Degradation (geology), 0210 nano-technology, Water vapor, Perovskite (structure)

الوصف: We have developed a vacuum-compatible chamber for in-situ X-ray diffraction (XRD) studies and have used it to characterize the changing crystal structure of an inorganic–organic hybrid perovskite material, CH3NH3PbI3 (MAPbI3), during interactions with water vapor at room temperature. In the XRD spectra, we have observed the degradation of MAPbI3 and the creation of MAPbI3 hydrates, which follow simple rate equations. The time constant for the degradation of MAPbI3 during accelerated aging suggests that multiple collisions of water molecules with the MAPbI3 crystal trigger the degradation of the crystal.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::0bd7eb4cc6b16fd4d12bb7376a0fe2acTest
https://doi.org/10.7567/jjap.57.028001Test

المؤلفون: Mitsunobu Yoshida, Toru Iijima, Yasuhiko Hayashi, P. S. Karthik, Zaw Lin, Masaki Hada, Takeshi Nishikawa

المصدر: Japanese Journal of Applied Physics. 56:01AB08

مصطلحات موضوعية: Flocculation, Ozone, Atmospheric pressure, Precipitation (chemistry), Inorganic chemistry, General Engineering, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Dielectric barrier discharge, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Chemical engineering, Surface modification, 0210 nano-technology, Dispersion (chemistry), Carbon

الوصف: In this paper, we describe the effects of helium plasma and ozone treatments on the dispersibility of carbon nanohorns (CNHs) in water. The experimental setups have been designed to efficiently generate helium plasma and ozone by dielectric barrier discharge at atmospheric pressure. After being treated with ozone, the oxygen-containing functional groups were introduced to the surface of CNHs, and are responsible for better dispersion. Helium plasma treatment was performed separately and it resulted in hydroxyl functional groups on the surface of CNHs. It was also found that the sizes of CNHs in water were smaller after ozone treatment. However, plasma-treated CNHs were bigger than ozone treated CNHs. The dispersed CNHs modified by ozone treatment were stable for more than three months without precipitation. In contrast, though helium plasma treatment introduced hydroxyl groups to the surface of CNHs, the dispersibility decreased and the flocculation of CNHs was observed in a few minutes.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::62dab326cf67c515a690580537505125Test
https://doi.org/10.7567/jjap.56.01ab08Test

المؤلفون: Hirokatsu Yashiro, Kozo Onoue, Takeshi Nishikawa, Masakazu Katsuno, Masatoshi Kanaya, Noboru Ohtani

المصدر: Japanese Journal of Applied Physics. 35:2240

مصطلحات موضوعية: Kinetics, Inorganic chemistry, Doping, General Engineering, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, Nitrogen, stomatognathic system, chemistry, Normal growth, Sublimation (phase transition), Growth rate, Polarite, Single crystal

الوصف: Nitrogen incorporation kinetics during the sublimation boule growth of SiC have been studied in terms of several growth parameters. 6H and 4H SiC crystals were heavily doped with nitrogen as a donor. It was found that the growth rate has little influence on the doping concentration, indicating that nitrogen incorporation is not kinetically limited at normal growth rates in the sublimation growth. On the other hand, surface polarity and polytype were found to influence the nitrogen incorporation kinetics at the growth front. By optimizing the growth conditions, bulk resistivities as low as 7.6×10-3 Ω cm and 5.3×10-3 Ω cm were obtained for 6H and 4H SiC, respectively.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::176f7b8f8717f54e263f12f0f1aba6bcTest
https://doi.org/10.1143/jjap.35.2240Test

المؤلفون: Takeshi Nishikawa, Toshihiro Kotani, Tada Koji, Hiromi Takei

المصدر: Japanese Journal of Applied Physics. 29:L902

مصطلحات موضوعية: Crystal, Crystallography, Lattice constant, Transmission electron microscopy, Chemistry, X-ray crystallography, General Engineering, General Physics and Astronomy, Energy filtered transmission electron microscopy, Crystal structure, Microstructure, Single crystal

الوصف: The microstructure of Tl2Ca3Ba2Cu4O x (2324-phase) single crystals grown by the slow-cooling method was investigated using transmission microscopy. These single crystals showed superconducting onset transition temperatures of 113 to 115 K, and lattice constants were a=b=3.85 Å and c=42.0 Å by X-ray diffraction measurement. The high-resolution transmission electron microscopy (TEM) observations revealed intergrowths of Tl-O single-layered structures, 1324 and 1425, with stacking spacings of 19 Å and 22 Å, in addition to a 2223 phase of 36 Å.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a3610a44ab28b3a4840d12eb398bb46dTest
https://doi.org/10.1143/jjap.29.l902Test

المؤلفون: Masaki Hada, Yoichi Hasegawa, Ryota Nagaoka, Tomoya Miyake, Ulugbek Abdullaev, Hiromi Ota, Takeshi Nishikawa, Yoshifumi Yamashita, Yasuhiko Hayashi

المصدر: Japanese Journal of Applied Physics; Feb2018, Vol. 57 Issue 2, p1-1, 1p

مستخلص: We have developed a vacuum-compatible chamber for in-situ X-ray diffraction (XRD) studies and have used it to characterize the changing crystal structure of an inorganic–organic hybrid perovskite material, CH3NH3PbI3 (MAPbI3), during interactions with water vapor at room temperature. In the XRD spectra, we have observed the degradation of MAPbI3 and the creation of MAPbI3 hydrates, which follow simple rate equations. The time constant for the degradation of MAPbI3 during accelerated aging suggests that multiple collisions of water molecules with the MAPbI3 crystal trigger the degradation of the crystal. [ABSTRACT FROM AUTHOR]

: Copyright of Japanese Journal of Applied Physics is the property of IOP Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Takeshi Nishikawa, Hideaki Takabe, Kunioki Mima

المصدر: Japanese Journal of Applied Physics. 28:2004

مصطلحات موضوعية: Neutron yield, Physics::Plasma Physics, Chemistry, Physics::Space Physics, General Engineering, Kinetic theory of gases, General Physics and Astronomy, Nuclear fusion, Implosion, Plasma, Atomic physics, Kinetic energy, Ion

الوصف: The non-Maxwellian effect of D-T ions in an inertially confined plasma was studied, and it was found that the reduction of the fusion reaction rate due to such a non-Maxwellian effect in the recent high-neutron-yield implosion experiments is not so drastic. Although the nonuniformity effect actually seems to be the main reason for explaining the difference of the neutron yield between the experiment and the 1-D simulation, the difference of a factor of 0.6∼0.7 in neutron yield can be explained by taking account of such a non-Maxwellian effect.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::986a75105a49258171e805758f37e91cTest
https://doi.org/10.1143/jjap.28.2004Test

المؤلفون: Takeshi Hikata, Hajime Hitotsuyanagi, Kenichi Sato, Takeshi Nishikawa, Hidehito Mukai

المصدر: Japanese Journal of Applied Physics. 28:L1204

مصطلحات موضوعية: Superconductivity, Flux pinning, High-temperature superconductivity, Condensed matter physics, Chemistry, Superconducting wire, General Engineering, General Physics and Astronomy, engineering.material, Magnetic field, law.invention, Transmission electron microscopy, law, Condensed Matter::Superconductivity, engineering, Grain boundary, Current density

الوصف: The critical current density (J c) in Ag-sheathed Bi-Pb-Sr-Ca-Cu-O superconducting wire increased to 17,400 A/cm2 in a zero magnetic field. The magnetic field dependence of J c was improved according to the increase of J c in a zero magnetic field. Fine, dispersed, nonsuperconducting phases were observed through SEM and TEM. These phases are expected to act as pinning sites.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::6978acd0d36476e839985a037a6a51b4Test
https://doi.org/10.1143/jjap.28.l1204Test

المؤلفون: Zaw Lin, Toru Iijima, Paneer Selvam Karthik, Mitsunobu Yoshida, Masaki Hada, Takeshi Nishikawa, Yasuhiko Hayashi

المصدر: Japanese Journal of Applied Physics; Jan2017, Vol. 56 Issue 1S, p1-1, 1p

مستخلص: In this paper, we describe the effects of helium plasma and ozone treatments on the dispersibility of carbon nanohorns (CNHs) in water. The experimental setups have been designed to efficiently generate helium plasma and ozone by dielectric barrier discharge at atmospheric pressure. After being treated with ozone, the oxygen-containing functional groups were introduced to the surface of CNHs, and are responsible for better dispersion. Helium plasma treatment was performed separately and it resulted in hydroxyl functional groups on the surface of CNHs. It was also found that the sizes of CNHs in water were smaller after ozone treatment. However, plasma-treated CNHs were bigger than ozone treated CNHs. The dispersed CNHs modified by ozone treatment were stable for more than three months without precipitation. In contrast, though helium plasma treatment introduced hydroxyl groups to the surface of CNHs, the dispersibility decreased and the flocculation of CNHs was observed in a few minutes. [ABSTRACT FROM AUTHOR]

: Copyright of Japanese Journal of Applied Physics is the property of IOP Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)