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molecules and studied in real time and in situ using synchrotron XPSHarries, J.; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
We exposed an Al(111) surface to a supersonic beam of molecular nitrogen. The uptake curve was followed using synchrotron radiation X-ray photo-electron spectroscopy. For a kinetic energy of 2.0 eV, higher than the reaction threshold of 1.8 eV, the uptake curve was linear, suggesting that nitrogen penetrates the bulk. This was confirmed by performing a depth-profile study using angle-resolved photo-electron spectroscopy.
in Fe
and Fe
of LuFe
O
Agui, Akane; Mizumaki, Masaichiro*; Ikeda, Naoshi*; Uozumi, Takayuki*; K
mbre, T.*
no journal, ,
The charge-frustrated system Lu FeO is characterized by a regular arrangement of Fe and Fe ions on the frustrated triangle lattice and it had reported the charge order of Fe and Fe causes its ferroelectricity. In order to investigate the Fe 3 state in the frustrated system, Fe La,b emission spectra and Fe L2,3 absorption spectra of LuFe+Fe
+O, LuGaFe+O and LuFe+CoO at I511-3 at MAXLAB and 7.0.1 at ALS. It was found that the profile of Fe La,b emission spectra of LuFeFeO is not simple superposition of Fe and Fe electronic states.
Izumi, Yudai*; Tanabe, Maiko*; Imazu, Akiko*; Mimoto, Aki*; Nakagawa, Kazumichi*; Tanaka, Masahito*; Agui, Akane; Muro, Takayuki*
no journal, ,
We measured soft X-ray natural circular dichroism (SXNCD) of aspartic acid (Asp) and tyrosine (Tyr) at oxygen K-edge region, in an attempt to obtain chiral structure at the vicinity of oxygen atoms. SXNCD measurement was carried out at the BL25SU beamline of the SPring-8, Japan. We focused on oxygen COO
1s 
transitions around 533 eV. Since we used sublimation films which are randomly oriented samples, we could reject E1E2 mechanism and pick up only E1M1 mechanism.
fluorescence following O(1s) excitation/ionisation in gas-phase water moleculesHarries, J.; Gejo, Tatsuo*; Sullivan, J. P.*; Azuma, Yoshiro*
no journal, ,
In this research we have obtained new information on the photo-dissociation dynamics of the water molecule following O (1s) inner-shell excitation/ionisation. When the O 1s electron is excited neutral excited H atoms can be produced. By investigating which states these H atoms are information can be obtained on the dissociation routes. When the inner-shell O 1s electron is excited/ionises, an unstable HO
ion core is formed. This is unstable, and Auger decay occurs. The resulting HO ion core dissociates, and one of the fragments can capture the initially excited electron. When this fragment is H, a neutral H atom is formed. In this research we use the pulsed nature of synchrotron radiation to study the lifetimes of the fluorescing excited states produced.
Fujii, Kentaro; Yokoya, Akinari
no journal, ,
To investigate the mechanism of the molecular change in DNA irradiated with the soft X-rays, we have measured the spectra of the X-ray absorption near edge structure (XANES) of DNA caused by exposure to monochromatic soft X-rays. We used a calf thymus DNA and oligonucleotide thin films as samples and observed N K-shell and O K-shell XANES spectral changes. The typical monochromatic soft X-ray energies used for the irradiation (380, 435, 560, and 760eV) were obtained from SPring-8, BL23SU. The observed spectra showed that initiation of the new products by the irradiation in the irradiated sample and the dissociation of molecular structure of the DNA by the irradiation. By comparison of these XANES spectral changes with the yields of base lesions and strand breaks as final products, we will discuss the molecular structure of DNA damage site and the site selectivity of damage induction in DNA by soft X-rays.
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Narita, Ayumi; Mannan, M. A.*; Koswattage, K.
no journal, ,
Recently much higher-quality thin films are needed in the field of organic semiconductor development. We report on the project started recently: Method to map direction of chemical -bonds in nanometer scale. We are striving to develop a unique instrument to measure polarization-angle dependence of Near-edge X-ray absorption fine structure (NEXAFS) spectra at nano-meter level using photoelectron emission microscopy (PEEM), in order to understand creation and growth mechanisms of oriented domains. It is possible to measure XAFS spectra of microscopic regions magnified by the PEEM scope. The most unique point is the fact that the PEEM column can be rotated along the axis of synchrotron beam, so that one can measure polarization-angle dependences of such micro-XAFS spectra. Moreover, we demonstrate that other experimental and theoretical methods which provide complementary information for chemical and electronic states of organic films.