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Arai, Taiki*; Yoshigoe, Akitaka; Motohashi, Mitsuya*
Zairyo No Kagaku To Kogaku, 60(5), p.153 - 158, 2023/10
Si oxide films are currently widely used as insulating materials in electronic devices and biomaterials. The atomic bonding state of these films significantly influences the properties of each device, thus it is particularly necessary to understand and control the chemical bonding state between Si and O in the films. In this study, the Si oxide films formed by anodic oxidation on Si substrate surfaces in extremely low concentrations of HF solutions were analyzed by X-ray photoelectron spectroscopy mainly focusing on Si2p and F1s spectra. Although the HF concentration is in the order of ppm, the films contain percent order of F atoms, suggesting the formation of Si-F and Si-O-F bonds in the films. It was also found that the different depth profiles for F and O atoms was observed, indicating that the surface reaction processes seem to be different depending on each element.
Sekiguchi, Tetsuhiro; Yokoyama, Keiichi; Yaita, Tsuyoshi
e-Journal of Surface Science and Nanotechnology (Internet), 20(3), p.186 - 195, 2022/07
Cesium-135 having long life, 2.3 million y, that is contained in nuclear wastes may cause long-term pollution. Technology of isotopic separation of such long lived nuclide is indispensable not only for its volume reduction but also annihilation by nuclear transmutation. The recovery of atomic Cs from molecular CsI is mandatory. We have investigated fullerene C
as a potential absorber for Cs. Angle-resolved X-ray photoelectron spectroscopy, AR-XPS has been used to analyze the depth concentration distribution of Cs. Experiments were performed at soft X-ray beamline BL27A at KEK PF facility. We report on the annealing effect after deposition of Cs and the effect of heating substrate during deposition. For Cs/C sample, the intensity ratio of Cs-3d/C-1s increased in double at the high temperature. This suggests that Cs atoms remain in the material at high temperatures. On the other hand, for CsI/C, the intensity ratio does not change much by elevating temperatures.
Kobata, Masaaki; Okane, Tetsuo; Kobayashi, Keisuke*
Bunko Kenkyu, 67(4), p.161 - 162, 2018/08
We introduce hard X-ray photoelectron spectroscopy, which has been rapidly introduced and developed in synchrotron radiation facilities. In particular, in order to realize electronic state analysis by hard X-ray photoelectron spectroscopy of insulators, the developed charge neutralization method was described. As an example, we showed adsorption behavior of cesium to nuclear reactor structure assuming Fukushima Daiichi Nuclear Power Plant accident. Finally, future prospects of hard X-ray photoelectron spectroscopy will be described.
Kobata, Masaaki; Okane, Tetsuo; Nakajima, Kunihisa; Suzuki, Eriko; Owada, Kenji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Osaka, Masahiko
Journal of Nuclear Materials, 498, p.387 - 394, 2018/01
Times Cited Count：18 Percentile：86.32(Materials Science, Multidisciplinary)In this study, for the understandings of Cesium (Cs) adsorption behavior on structure materials in severe accidents at a light water nuclear reactor, the chemical state of Cs and its distribution on the surface of SUS304 stainless steel (SS) with different Si concentration were investigated by hard X-ray photoelectron spectroscopy (HAXPES) and scanning electron microscope / energy dispersive X-ray spectroscopy (SEM/EDX). As a result, it was found that Cs is selectively adsorbed at the site where Si distributes with high concentration. CsFeSiO
is a dominant Cs products in the case of low Si content, mainly formed, while Cs
SiO
and CsSiO
are formed in addition to CsFeSiO in the case of high Si content. The chemical forms of the Cs compounds produced in the adsorption process on the SS surface has a close correlation with the concentration and chemical states of Si originally included in SS.
-Ti
O
and 
-TiO studied by hard X-ray photoelectron spectroscopyKobayashi, Keisuke*; Taguchi, Munetaka*; Kobata, Masaaki; Tanaka, Kenji*; Tokoro, Hiroko*; Daimon, Hiroshi*; Okane, Tetsuo; Yamagami, Hiroshi; Ikenaga, Eiji*; Okoshi, Shinichi*
Physical Review B, 95(8), p.085133_1 - 085133_7, 2017/02
Times Cited Count：15 Percentile：57.94(Materials Science, Multidisciplinary)Baba, Yuji; Shimoyama, Iwao; Hirao, Norie*
Applied Surface Science, 384, p.511 - 516, 2016/10
Times Cited Count：5 Percentile：25.78(Chemistry, Physical)Chemical states of cesium as well as the other alkali metals (sodium and rubidium) sorbed in micaceous oxides have been investigated by total reflection X-ray photoelectron spectroscopy (TR-XPS). For cesium, it was shown that ultra-trace amount of cesium down to about 100 pg/cm
can be detected by TR-XPS. This amount corresponds to about 200 Bq of 
Cs (t
= 30.2y). It was demonstrated that ultra-trace amount of cesium corresponding to radioactive cesium level can be measured by TR-XPS. As to the chemical states, it was found that core-level binding energy in TR-XPS for trace-level cesium shifted to lower-energy side compared with that for thicker layer. A reverse tendency is observed in sodium. Based on charge transfer within a simple point-charge model, it is concluded that chemical bond between alkali metal and micaceous oxide for ultra-thin layer is more polarized that for thick layer.
and O/HO adsorption revealed by in situ XAFS and hard X-ray photoelectron spectroscopyCui, Y.*; Harada, Yoshihisa*; Hatanaka, Tatsuya*; Nakamura, Naoki*; Ando, Masaki*; Yoshida, Toshihiko*; Ikenaga, Eiji*; Ishii, Kenji*; Matsumura, Daiju; Li, R.*; et al.
ECS Transactions, 72(8), p.131 - 136, 2016/10
Times Cited Count：1 Percentile：48.67(Electrochemistry)Esaka, Fumitaka
Ekisupato Oyo Kagaku Sirizu; Kiki Bunseki, p.119 - 135, 2015/09
Bulk analysis has been conventionally used for measuring solid materials. In contrast, surface analysis is extensively used for analyzing chemical compositions and chemical states of solid surface. The surface compositions often differ from those of bulk materials. Recently, doping of impurity elements and deposition of thin films on the surface of the materials are key techniques to fabricate functional materials. Therefore, surface analysis becomes important to characterize such materials. In this paper, the principle and feature of some surface analytical techniques are described.
Mannan, M. A.*; Baba, Yuji; Kida, Tetsuya*; Nagano, Masamitsu*; Noguchi, Hideyuki*
Materials Sciences and Applications, 6(5), p.353 - 359, 2015/05
The synthesis and structure of hexagonal boron carbonitride (h-BCN) film on polycrystalline diamond surface were reported. Polycrystalline diamond and/or diamond-like carbon were first fabricated on Si (100) and then it was used as substrate. The deposition was performed by radio frequency plasma enhanced chemical vapor deposition. In order to reduce the content of nitrogen void defects, the deposition was performed at the high temperature of 950
C under the working pressure of 2.6 Pa. The typical sample with atomic composition of B
C
N
O
in the h-BCN lattice was characterized by X-ray photoelectron spectroscopy. The fine structure of the film was studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The B K-edge and N K-edge of NEXAFS spectra revealed that the synthesized h-BCN film has the ideal honeycomb-like BN
configuration without nitrogen void defects.
Kobata, Masaaki; Kobayashi, Keisuke*
Journal of the Vacuum Society of Japan, 58(2), p.43 - 49, 2015/02
We report the applications of a hard X-ray photoelectron spectroscopy to the characterization of SiO/Si(001)systems. Large escape depth of high-energy photoelectron enables us to probe buried layers and their interfaces in multilayer structures. Estimation of SiO overlayer thicknesses up to 25 nm by angle resolved XPS was possible in SiO/Si(001) samples. Determination of the thickness profile of a wedged shape SiO buried layer was successfully done in Ir (8 nm)/HfO (2.2 nm)/thickness graded-SiO (0-10 nm) / Si (100). The Si 1s core level showed a SiO thickness dependent shift, which was ascribed to fixed charge at the SiO-Si interface. Energy distribution of interface states at ultrathin thermal oxide/Si(100) interfaces were determined by Si 1
core level shift by applying gate bias in metal-oxide-semiconductor (MOS) structure with 5 nm Au gate electrodes.
-FeSi thin film formation processesYamamoto, Hiroyuki; Yamaguchi, Kenji; Hojo, Kiichi
Thin Solid Films, 461(1), p.99 - 105, 2004/08
Times Cited Count：10 Percentile：46.79(Materials Science, Multidisciplinary)no abstracts in English
Shimoyama, Iwao; Baba, Yuji; Sekiguchi, Tetsuhiro; Nath, K. G.; Sasaki, Masayoshi*; Okuno, Kenji*
Journal of Vacuum Science and Technology A, 21(6), p.1843 - 1848, 2003/11
Times Cited Count：6 Percentile：28.14(Materials Science, Coatings & Films)Ion implantation method is applied to synthesize B-C-N hybrids and their electronic structures are characterized by X-ray photoelectron spectroscopy. A boron nitride film is deposited on a graphite target by borazine plasma implantation. At the interface between the BN film and the graphite, variety of bonding combinations including B-N, B-C, and C-N are observed. This proved that B-C-N hybrids is formed by this method.
Morimoto, Yasutomi*; Sasaki, Masayoshi*; Kimura, Hiromi*; Sakamoto, Keishi; Imai, Tsuyoshi; Okuno, Kenji*
Fusion Engineering and Design, 66-68, p.651 - 656, 2003/09
Times Cited Count：3 Percentile：25.75(Nuclear Science & Technology)no abstracts in English
at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiationYoshigoe, Akitaka; Teraoka, Yuden
Surface Science, 482-485(Part.1), p.189 - 195, 2001/06
no abstracts in English
Yamamoto, Hiroyuki; Baba, Yuji
Journal of the Korean Vacuum Society, 9(S2), p.84 - 88, 2000/11
no abstracts in English
/Si layer by high-energy XPSYamamoto, Hiroyuki; Baba, Yuji
Journal of Surface Analysis, 7(1), p.122 - 127, 2000/03
no abstracts in English
; Kubota, Mitsuru*; *; *
JNC TN8430 98-001, 12 Pages, 1998/11
Leaching experiments were performed with simulated nuclear waste glasses in silica saturated water at 90C for periods of 28 days in order to clarify the alteration mechanism of waste glass under silica saturation. After leaching experiments, the depth profiles of some elements of glass surfaces were measured by ERDA and ESCA. Depth profiles of H and soluble elements, such as B and Na, for the simulated nuclear waste glass after leaching experiments demonstrated the formation of glass hydration layer and the depletion of soluble elements in the glass hydration layer. The results suggest that alteration of nuclear waste glass under silica saturation is attributed to glass hydration and the leaching behaviour of soluble elements depends on the growth of the glass hydration layer.
Shimogori, Kazutoshi*; Tomari, Haruo*; *; Fujiwara, Kazuo*; Masugata, Tsuyoshi*
PNC TJ1074 98-002, 270 Pages, 1998/02
None
; Kusaka, Makoto*
JAERI-Tech 97-025, 20 Pages, 1997/07
no abstracts in English
Yamamoto, Hiroyuki; Baba, Yuji; Sasaki, Teikichi
Photon Factory Activity Report, P. 366, 1995/00
no abstracts in English
