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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:19.38(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
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:0.00(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
Times Cited Count:11 Percentile:42.94(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.
Tode, 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 (VCr
Ti
) 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 Al
O
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 (Al
O
, Ti
O
, 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.
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.
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, ,
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.
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.
Tagawa, Masahito*; Yokota, Kumiko*; Furuyama, Yuichi*; Kanda, Kazuhiro*; Tode, Mayumi; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Effects of vacuum ultraviolet and surface oxide layer on the hydrogen desorption from hydrogenated diamond-like carbon (HDLC) films were investigated. We have used commercially available HDLC as a specimen, and synchrotron radiation at BL-6 in NewSUBARU or D lamp as an external source of photon energy. SiO
and TiO
surface oxide films with a few nanometer thickness were formed by irradiation of hyperthermal atomic oxygen beams with a translational energy of approximately 5 eV onto metal-doped HDLCs in order to investigate the effect of oxide film on the hydrogen desorption. It was confirmed that the effect of SiO
and TiO
gave different influence on desorption temperature of hydrogen.
Tagawa, Masahito*; Yokota, Kumiko*; Furuyama, Yuichi*; Tode, Mayumi; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
In order to make clear an effect of surface oxide layers for hydrogen desorption processes of hydrogen storage materials, ultra-thin metal oxide layers were formed on diamond-like-carbon (DLC) surfaces containing hydrogen and metals by irradiation of atomic oxygen beams. The thickness of SiO layer formed by the atomic oxygen beam irradiation was estimated to be about 4.5-6.5 nm on the basis of Si
/Si
photoemission peak area ratio. This value is larger than the diffusion depth of oxygen atoms in an Si crystal at a room temperature. Thermal desorption gas analyses revealed that a hydrogen desorption temperature did not change by the atomic oxygen beam irradiation. However, a hydrogen desorption temperature decreased in the atomic oxygen beam irradiation to a DLC containing Ti. The variation of hydrogen desorption temperature depends on a kind of metal oxide layer.
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, ,
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, ,
In order to study the relationships between the thermal desorption of hydrogen and the surface properties, we have used high-resolution synchrotron radiation X-ray photoelectron spectroscopy to study the thermal degeneration processes of the surface layers. The experiments were performed at the JAEA soft X-ray beamline BL23SU at SPring-8, using the "SUREAC2000" surface reaction analysis apparatus. XPS spectra were recorded for room temperature TiFe and VCr
Ti
following flash heating to 373-1073 K. Spectra were recorded for two samples covered with native oxide layers, one of which was implanted with deuterium ions. In the deuterium-implanted TiFe, the temperature to which it begins to resolve the oxide component has lowered at about 200-250
C. On the other hand, in VCrTi, the thermal stability of a surface natural oxide layer has increased by the deuterium-implanted.
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.
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 relationships between the thermal desorption of hydrogen and the surface properties we have used high-resolution synchrotron radiation X-ray photoelectron spectroscopy to study the thermal degeneration processes of the surface layers. 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 (VCr
Ti
) 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.