Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tanaka, Hirohisa*; Masaki, Sayaka*; Aotani, Takuro*; Inagawa, Kohei*; Iwata, Sogo*; Aida, Tatsuya*; Yamamoto, Tadasuke*; Kita, Tomoaki*; Ono, Hitomi*; Takenaka, Keisuke*; et al.
SAE Technical Paper 2022-01-0534 (Internet), 10 Pages, 2022/03
NaTiO
Yoneda, Yasuhiro; Nagata, Hajime*; Takenaka, Tadashi*
Journal of the Korean Physical Society, 66(9), p.1339 - 1343, 2015/05
Times Cited Count：5 Percentile：40.49(Physics, Multidisciplinary)The potential lead-free piezoelectric material bismuth sodium titanate, BiNaTiO (BNT), was investigated by means of high-energy synchrotron X-ray diffraction. BNT has been assumed thus far to exhibit the rhombohedral space group 
at room temperature. Recently, the average structure of BNT was described by the monoclinic space group 
. We performed local structure analysis of BNT using atomic pair-distribution function method. The ground state of BNT was found to be rhombohedral structure in which bismuth and sodium atoms were chemically ordered in the perovskite 
-site.
Yoneda, Yasuhiro; Kohara, Shinji*; Nagata, Hajime*; Fu, D.*; Takenaka, Tadashi*
Transactions of the Materials Research Society of Japan, 39(4), p.455 - 458, 2014/12
NaNbO, KNbO, and AgNbO have rhombohedral structure at low temperatures. The phase transition depends on -site ion with NbO
octahedron. NaNbO and KNbO have structural phase transition from rhombohedral to orthorhombic with increasing temperature. On the other hand, the phase transition of AgNbO occurs from rhombohedral to monoclinic. Since the rhombohedral structure is a highly ordered average structure, it tends to be subject to the influence of local randomness. We performed local structure analysis by using atomic pair-distribution function (PDF). The Nb-O bond clearly appeared in the observed distribution for NaNbO, but degraded in that for AgNbO. The difference of local structures causes different successive phase transitions for the Nb-related perovskite materials.
Na)TiO and NaNbOYoneda, Yasuhiro; Aoyagi, Rintaro*; Fu, D.*; Takenaka, Tadashi*
Transactions of the Materials Research Society of Japan, 39(3), p.247 - 250, 2014/09
BiNaTiO and NaNbO are 
O perovskite ferroelectric materials and they are considered to be promising lead-free ferroelectric materials because of their relatively high piezoelectric properties in lead-free piezoelectric ceramics. The purpose of this work was to clarify the local structures of Li-substituted BiNaTiO and NaNbO to elucidate the mechanism of the stabilization of the ordered ferroelectric phase.
Na)TiOYoneda, Yasuhiro; Hiruma, Yuji*; Nagata, Hajime*; Takenaka, Tadashi*
Japanese Journal of Applied Physics, 49(9), p.09ME09_1 - 09ME09_4, 2010/10
Times Cited Count：12 Percentile：45.82(Physics, Applied)(BaNa)TiO was carried out by a synchrotron radiation X-ray pair-distribution function (PDF) method. The PDF peak is resolved as a doublet owing to the presence of two phases with distinct local structures, those are rhombohedral and tetragonal phases. The dominant rhombohedral phase is stabilized by the Li substitution. The depolarization temperature (
) is increased as increasing the rhombohedral component in the local structure.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Kawai, Masayoshi*; Furusaka, Michihiro*; Kikuchi, Kenji; Kurishita, Hiroaki*; Watanabe, Ryuzo*; Li, J.*; Sugimoto, Katsuhisa*; Yamamura, Tsutomu*; Hiraoka, Yutaka*; Abe, Katsunori*; et al.
Journal of Nuclear Materials, 318, p.35 - 55, 2003/05
R&D works for MW class solid target composed of tungsten to produce pulsed intense neutron source has been made in order to construct a future scattering facility. Three methods were investigated to prevent corrosion of tungsten from water; those are hipping, brazing and electric coating in molten salt bath. Hipping condition was optimized to be 1500 degree C in the previous work: here small punch test shows highest load for crack initiation of hipped materials at the boundary of W/Ta. The basic techniques for the other two methods were developed. Erosion test showed that uncovered W is susceptible of flowing water velocity. At high velocity w is easy to be eroded. For solid target design slab type and rod type targets were studied. As long as the optimized neutron performance is concerned, 1MW solid target is better than mercury target.
Koike, Masato; Sano, Kazuo*; Yoda, Osamu; Harada, Yoshihisa*; Ishino, Masahiko; Moriya, Naoji*; Sasai, Hiroyuki*; Takenaka, Hisataka*; Gullikson, E. M.*; Mrowka, S.*; et al.
Review of Scientific Instruments, 73(3), p.1541 - 1544, 2002/03
Times Cited Count：20 Percentile：68.31(Instruments & Instrumentation)no abstracts in English
Tsunematsu, Toshihide; Namba, Haruyuki*; Akutsu, Yoichi; Okawa, Yoshinao; Yagenji, Akira; Takeda, Masatoshi*; Yajima, Kensaku*; Nitta, Yoshio*; Kobayashi, Kenichi*; Maeda, Ikuo*; et al.
Fusion Engineering and Design, 41(1-4), p.415 - 420, 1998/09
Times Cited Count：3 Percentile：31.85(Nuclear Science & Technology)no abstracts in English
Nishi, Yoshihisa*; *; Furuya, Masahiro*; *; Matsubayashi, Masahito; Tsuruno, Akira
Fifth World Conf. on Neutron Radiography, 0, p.548 - 555, 1996/00
no abstracts in English
Hayashida, Hirotoshi; Yamazaki, Dai; Ebisawa, Toru*; Maruyama, Ryuji; Soyama, Kazuhiko; Takenaka, Nobuyuki*; Kageyama, Masashi*; Tasaki, Seiji*; Hino, Masahiro*; Kawabata, Yuji*; et al.
no journal, ,
no abstracts in English
Hayashida, Hirotoshi; Yamazaki, Dai; Ebisawa, Toru*; Maruyama, Ryuji; Soyama, Kazuhiko; Iikura, Hiroshi; Yasuda, Ryo; Sakai, Takuro; Matsubayashi, Masahito; Takenaka, Nobuyuki*; et al.
no journal, ,
no abstracts in English
Hayashida, Hirotoshi; Yamazaki, Dai; Ebisawa, Toru*; Maruyama, Ryuji; Soyama, Kazuhiko; Iikura, Hiroshi; Yasuda, Ryo; Sakai, Takuro; Matsubayashi, Masahito; Takenaka, Nobuyuki*; et al.
no journal, ,
no abstracts in English
NaTiOYoneda, Yasuhiro; Hiruma, Yuji*; Nagata, Hajime*; Takenaka, Tadashi*
no journal, ,
BiNaTiO is paid to attention as an alternative material of PbTiO for the use of an piezoelectric oscillator. In the problem in use as the piezoelectric vibrator, the depolarization temperature is a low. A lot of attempts to increase the depolarization temperature have been performed. Being able to raise the depolarization temperature as an additive only is a lithium. We performed the structure analysis to clarify the T
increasing mechanism on Li-doped iNaTiO. As a result, Randomness owing to the deference between the ionic size of Na and Bi decreases from the structure though Li is doping done, and it has been understood that the order structure is predominant.
Hayashida, Hirotoshi; Yamazaki, Dai; Ebisawa, Toru*; Maruyama, Ryuji; Soyama, Kazuhiko; Iikura, Hiroshi; Yasuda, Ryo; Sakai, Takuro; Matsubayashi, Masahito; Takenaka, Nobuyuki*; et al.
no journal, ,
no abstracts in English
