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Teraoka, Yuden; Tode, Mayumi*; Harries, J.; Yoshigoe, Akitaka
Denki Gakkai Rombunshi, C, 134(4), p.473 - 478, 2014/04
Hashinokuchi, Michihiro*; Tode, Mayumi*; Yoshigoe, Akitaka; Teraoka, Yuden; Okada, Michio*
Applied Surface Science, 276, p.276 - 283, 2013/07
Times Cited Count：4 Percentile：20.56(Chemistry, Physical)Yokota, Kumiko*; Tagawa, Masahito*; Matsumoto, Koji*; Furuyama, Yuichi*; Kitamura, Akira*; Kanda, Kazuhiro*; Tode, Mayumi; Yoshigoe, Akitaka; Teraoka, Yuden
Protection of Materials and Structures from the Space Environment; Astrophysics and Space Science Proceedings, Vol.32, p.531 - 539, 2012/08
Cr
Ti
Harries, J.; Teraoka, Yuden; Tode, Mayumi; Yoshigoe, Akitaka
Applied Physics Express, 5(3), p.031802_1 - 031802_3, 2012/03
Times Cited Count：0 Percentile：0(Physics, Applied)Kanda, Kazuhiro*; Yokota, Kumiko*; Tagawa, Masahito*; Tode, Mayumi; Teraoka, Yuden; Matsui, Shinji*
Japanese Journal of Applied Physics, 50(5), p.055801_1 - 055801_3, 2011/05
Recently, the irradiation of soft X-ray synchrotron radiation (SR) to highly-hydrogenated diamond-like-carbon (H-DLC) films in vacuum results in the desorption of hydrogen and the increase of film density, hardness and refractive index. In this study, we investigated SR irradiation effects on the H-DLC with different hydrogen contents. The H-DLC thin films were deposited on an Si wafer with 200 nm thickness by an amplitude-modulated radio frequency plasma chemical vapor deposition method. The SR irradiation was carried out at NewSUBARU BL6. The SR has a continuous spectrum from IR to soft X-ray, which is lower than 1 keV. The hydrogen content dependence on SR dose was estimated using elastic recoil detection analysis (ERDA) and Rutherford backscattering (RBS) techniques. The hydrogen content was kept constant in the low-hydrogenated DLC film, while that in the high-hydrogenated DLC film decreased exponentially with soft X-ray dose.
Kanda, Kazuhiro*; Yokota, Kumiko*; Tagawa, Masahito*; Tode, Mayumi; Teraoka, Yuden; Matsui, Shinji*
Japanese Journal of Applied Physics, 50(5), p.055801_1 - 055801_3, 2011/05
Times Cited Count：11 Percentile：43.98(Physics, Applied)CrTi using synchrotron radiation photoelectron spectroscopyTode, Mayumi; Harries, J.; Teraoka, Yuden; Yoshigoe, Akitaka
Denki Gakkai Rombunshi, C, 130(10), p.1819 - 1820, 2010/10
In order to study the thermal degradation process of the hydrogen storage materials surface layer and the thermal desorption of hydrogen property, we have used high-resolution synchrotron radiation X-ray photoelectron spectroscopy. The experiments were performed at the JAEA soft X-ray beamline BL23SU at SPring-8, using the "SUREAC2000" surface reaction analysis apparatus. Spectra were recorded for two samples (VCrTi) covered with native oxide layers, one of which was implanted with deuterium ions. For the un-implanted sample, the oxide layer changes dramatically between 373 K and 473 K, for the deuterium-implanted sample, the change occurs between 473 K and 573 K. The implantation of deuterium leads to a stabilization (of approximately 100 K) of the surface oxide layer.
Hashinokuchi, Michihiro*; Sumimoto, Yuichi*; Tode, Mayumi; Harries, J.; Okada, Michio*; Teraoka, Yuden; Kasai, Toshio*
Denki Gakkai Rombunshi, C, 130(10), p.1723 - 1729, 2010/10
The oxidation processes on a TiAl surface induced by a hyperthermal O
molecular beam (HOMB) with a translational energy of 2.2 eV was studied by X-ray photoemission spectroscopy in conjunction with synchrotron radiation. At a surface temperature of 300 K, the simultaneous growth of Al and Ti oxides accompanied with the segregation of AlO
near the surface was observed. The efficiency of oxidation for the HOMB incidence was smaller than that for O backfilling (25 meV). Furthermore, the chemical compositions of oxide species (AlO, TiO, TiO) on the TiAl surface were independent of the translational energy of incident O molecule. The present results suggest that the oxidation on TiAl surface proceeds via precursor molecular states.
Hashinokuchi, Michihiro*; Sumimoto, Yuichi; Tode, Mayumi; Okada, Michio*; Harries, J.; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Toshio*
no journal, ,
We have studied chemical reactions of TiAl surface with oxygen molecules by using synchrotron radiation photoelectron spectroscopy to clarify the generation process of Al oxides. The experiment was conducted with the surface chemistry experimental station (SUREAC2000) at the soft X-ray beamline (BL23SU) of Japan Atomic Energy Agency in the SPring-8 facilities. The surface (50at.%) was cleaned by Ar
ion sputtering and annealing. Comparing the Al-2p and Ti-2p XPS spectra of the clean surface with those of the surface exposed to the oxygen of 350L at 673K, it has been found that the peak position and profile were changed. It shows that both Ti and Al atoms were oxidized. Moreover, the Ti oxides was decreased by heating up to 1123K.
Harries, J.; Tode, Mayumi; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Photoelectron spectroscopy is predominantly a surface-sensitive technique, but by recording spectra at a range of angles information on the depth-dependent distribution of elements in specific chemical states can also be obtained. Compared to other techniques such as Rutherford back-scattering, the technique has the advantage of chemical-state specificity, but the drawback that it requires very careful data analysis to produce reliable and quantitative results. Here we report progress in obtaining chemical-state depth profiles from photoelectron spectra recorded using the SUREAC2000 apparatus at SPring-8's BL23SU. Results will be presented for ARXPS data recorded for N and O layers on Al(111), and also a VCrTi sample, both in its as-received state and following deuterium ion dosing.
Tode, Mayumi; Harries, J.; Teraoka, Yuden; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka
no journal, ,
Tode, Mayumi; Harries, J.; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
In order to study the correlation between the hydrogen desorption temperature and the chemical bonding states of the oxide layer, photoemission spectroscopy with soft X-ray synchrotron radiation has been applied for analyses of the native oxide on the polycrystalline VCrTi alloy surface and its thermal instability. Before thermal annealing, O-1s, V-2p, Cr-2p, and Ti-2p peak from the native oxide layer had been obtained with a photon energy of 1247 eV. O-1s, V-2p, Cr-2p, and the Ti-2p peak have changed by thermal annealing at 473 K. For the deuterium ion implanted surface, the O-1s, V-2p, Cr-2p, and Ti-2p peak kept its profile until 573 K. After desorption of D2 molecules at around 573 K, the native oxide layer started changing its structure. Consequently deuterium implantation affected the thermal stability of the native oxide.
Tode, Mayumi; Harries, J.; Teraoka, Yuden; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka
no journal, ,
Study of thermal desorption characteristics of native oxide layer on the surface of the hydrogen storage materials is very important. Thermal instability of native oxide layer on VCrTi and deuterated VCrTi was observed by high resolution soft X-ray synchrotron radiation photoemission spectroscopy. All experiments have been conducted at the surface chemistry experimental station (SUREAC2000) at BL23SU, SPring-8. Before thermal annealing, the satellite peak from the native oxide layer and the V-2p peak from the bulk were observed. The O-1s peak consisted of at least two components. After thermal annealing, the O-1s peak decreases and the V-2p peak increases. Deuterium implantation affected the thermal stability of the native oxide.
Harries, J.; Tode, Mayumi; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Using the high energy resolution surface chemistry apparatus at SPring-8's BL23SU it is possible to record angular and chemical-state resolved X-ray photoelectron spectra. Chemical-state specific depth profile information can be obtained from these spectra using the maximum entropy method. Here we describe progress made in the combination of these two techniques, with the specific example of the depth-profiling of various nitridation states present in a Al(111) sample nitrided using a supersonic molecular beam.
Harries, J.; Tode, Mayumi; Inoue, Keisuke; Sumimoto, Yuichi; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
There are many available methods for determining the elemental distributions within a sample in the depth direction, but angle-resolved X-ray photoelectron spectroscopy offers the advantage of chemica-state specificity. At the surface chemistry station at BL23SU, SPring-8, we have recorded depth-profiles for thin films generated using supersonic molecular beams and ion beams. To extract the depth-direction information from the angular resolved spectra we use the maximum entropy method. We explain the techniques, and present the specific example of the natural oxide of VCrTi, a hydrogen storage material. Also, we investigate the thermal stability of the oxide by generating depth profiles during annealing of the sample.
Teraoka, Yuden; Harries, J.; Tode, Mayumi; Yoshigoe, Akitaka
no journal, ,
Native oxides of VCrTi alloy, their thermal stability and their modification via deuterium ion implantation have been investigated using synchrotron radiation photoemission spectroscopy. The oxide thickness was estimated to be 3 nm by photon energy dependence (600 eV - 1600 eV). Its thermal stability was investigated by flash heating from 473 K to 1173 K. O1s, C1s, V2p, Cr2p, and Ti2p were measured after cooling down below 373 K. Before heating, major peaks of metal oxides were observed at 1247 eV as well as minor peaks showing their bulk contribution. After only 473 K heating, the metal peaks grew with O1s decrease. The same kind experiments were performed for deuterized samples with dose of 2.8
10
cm
. Photoemission peaks after 373 K heating were almost same as before heating in contrast to the non-ion-implanted sample. D desorption was observed by a mass spectrometer during 573 K heating. Consequently, the native oxide decomposeD thermally after D desorption.
Harries, J.; Teraoka, Yuden; Yoshigoe, Akitaka; Tode, Mayumi
no journal, ,
VCrTi is a candidate material for hydrogen storage, and as such information about its surface layer composition is essential. We have used angle-resolved photoelectron spectroscopy to obtain information on the depth distribution of the elements within the alloy, and their chemical states. Also, the changes in this composition are investigated as the temperature of the sample is raised in 100 degree increments up to 800 degrees Centigrade.
CrTi) using high-resolution soft X-ray synchrotron radiation photoelectron spectroscopyTode, Mayumi; Harries, J.; Teraoka, Yuden; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka
no journal, ,
Thermal stability of native oxide layer on the hydrogen storage materials is related to the hydrogen absorption and desorption. Thermal instability of native oxide layer on VCrTi and deuterated VCrTi was observed by high resolution soft X-ray synchrotron radiation photoemission spectroscopy. All experiments have been conducted at the surface chemistry experimental station (SUREAC2000) at BL23SU, SPring-8. After thermal annealing, the peak that shows the oxidation weakens, and the peak that shows the metal strengthens. The thermal stability of a natural oxide layer was observed to stabilize by about 100 degrees by deuterium ion implanted.
Tode, Mayumi; Harries, J.; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Thermal stability of native oxide layer on the hydrogen storage materials is related to the hydrogen absorption and desorption. In this study, thermal degradation process of native oxide layer on TiFe was observed by high resolution soft X-ray synchrotron radiation photoemission spectroscopy. All experiments have been conducted at the surface chemistry experimental station (SUREAC2000) at BL23SU, SPring-8. After thermal annealing, the peak that shows the oxidation weakens, and the peak that shows the metal strengthens. The thermal stability of a natural oxide layer was observed to stabilize by about 200 degrees by deuterium ion implanted.
Tode, Mayumi; Harries, J.; Teraoka, Yuden; Sumimoto, Yuichi; Inoue, Keisuke; Yoshigoe, Akitaka
no journal, ,
Thermal stability of native oxide layer on the hydrogen storage materials is related to the hydrogen absorption and desorption. In this study, thermal degradation process of native oxide layer on VCrTi was observed by high resolution soft X-ray synchrotron radiation photoemission spectroscopy. All experiments have been conducted at the surface chemistry experimental station (SUREAC2000) at BL23SU, SPring-8. Before thermal annealing, photoemission spectrum of oxide was observed. After thermal annealing, the oxide peak was decreased, and the metal peak was increased. When the deuterium ion was implanted into the surface, the degeneration temperature of a natural oxide layer was observed to rise about 100 degrees.
