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NaTiO
Yoneda, Yasuhiro; Noguchi, Yuji*
Japanese Journal of Applied Physics, 59(SP), p.SPPA01_1 - SPPA01_7, 2020/11
Times Cited Count：19 Percentile：77.19(Physics, Applied)We investigate A-site cation ordering in the ferroelectric perovskite BiNaTiO (BNT) by synchrotron X-ray total scattering. Although BNT has a problem of a low depolarization temperature, it is promising a lead-free piezoelectric material. Since the depolarization temperature is presumed to correspond to a relaxer like gradual order-disorder phase transition, local structure analysis is necessary to understand the structure of the diorder phase. Through this approach, the elusive connection between chemical heterogeneity and structural heterogeneity is revealed. Because of the large randomness, the Ti off-center shift is averaged out beyond the unit cell and the structure becomes very close to the average structure beyond the unit cell.
Hirade, Tetsuya
Journal of Physics; Conference Series, 618(1), p.012004_1 - 012004_5, 2015/06
Times Cited Count：5 Percentile：84.11(Physics, Applied)Positronium (Ps; a bound state of positron and electron) has a negative work function in materials and forms a bubble state in liquids. On the way of stable bubble state, the bubble grows and probably oscillates. The usual fast bubble formation has not been observed with the time resolution of the positron annihilation methods that is usually 100-200 pico-seconds. There had been many anomalous phenomena observed in the room temperature ionic liquids (RTIL). Recently it was found that very slow bubble formation caused these anomalous phenomena. And hence the oscillation of the Ps bubble was successfully observed by the change of the annihilation rate of the triplet Ps that is affected by the size of the bubble. The oscillation and the decay of the bubble give the information of the viscoelastic properties at the sub-nano scale. The temperature dependence of the oscillation has been also successfully indicated.
Li tracerIshiyama, Hironobu*; Jeong, S.-C.*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari*; Oyaizu, Mitsuhiro*; Katayama, Ichiro*; Osa, Akihiko; Otokawa, Yoshinori; et al.
Japanese Journal of Applied Physics, 53(11), p.110303_1 - 110303_4, 2014/11
Times Cited Count：4 Percentile：18.07(Physics, Applied)Nagashima, Keisuke; Kado, Masataka; Nishikino, Masaharu
JAERI-Research 2003-035, 10 Pages, 2004/02
JAERI-Research-2003-035.pdf:0.52MB
no abstracts in English
Yoshigoe, Akitaka
no journal, ,
In this conference on surface science, the results of pinpoint analysis of clay minerals artificially containing Cs using synchrotron radiation photoemission electron microscopy are talked as an invited lecture. Nano-scaled realspace analysis of distribution maps of the constituent elements and chemical states of both Cs and Fe atoms are described to discuss the model of Cs adsorption into clay minerals. Future perspective of the application of synchrotron radiation photoemission electron microscopy to various kinds of research fields are also talked.
Yoshigoe, Akitaka
no journal, ,
In this symposium, the results of nanoscale spatial analysis of clay minerals artificially containing Cs using synchrotron radiation photoemission electron microscopy are talked as an invited tutorial. Despite of its insulating properties, precise analysis of distribution maps of the constituent elements and chemical states of both Cs and Fe atoms were succeeded due to the proper sample treatments. The model of Cs adsorption into clay minerals is discussed based on the data of pinpoint X-ray absorption spectra for Cs and Fe core-levels. Future perspective of the application of synchrotron radiation photoemission electron microscopy are also talked.
Yoshigoe, Akitaka
no journal, ,
A synchrotron radiation photoemission electron microscope (SR-PEEM) probing photoelectrons emitted from samples is an useful microscope with surface sensitive and nanoscale spatial resolution. The electron lens-system facilitates the enlargement and reduction of the sample image, and enables pinpoint chemical analysis by high energy resolution X-ray absorption spectroscopy (XAS). It has many advantages over scanning and transmission microscopes because it can observe samples without any preparations such as reduction of the sample thickness. In this talk, an application of SR-PEEM for elucidation of the adsorption states of radioactive Cs in clay minerals due to 1F accident will be shown. To overcome insulating properties of clay, an thin film was deposited on the sample surface. After this treatment. clear Cs map and pinpoint XAS spectra for Cs M-edge XAS for weathered biotite clay minerals with Cs were obtained to giving important findings on Cs adsorption mechanism. This method is expected to be applicable for not only the nuclear power researches, but also studies on nanotechnologies.
Toyama, Takeshi*; Shibahara, Rie*; Du, Y.*; Inoue, Koji*; Nagai, Yasuyoshi*; Yano, Yasuhide; Otsuka, Satoshi; Mitsuhara, Masatoshi*; Nakashima, Hideharu*; Onuma, Masato*
no journal, ,
no abstracts in English
