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津田 泰孝; Gueriba, J. S.*; 植田 寛和*; Di
o, W. A.*; 倉橋 光紀*; 岡田 美智雄*
JACS Au (Internet), 2(8), p.1839 - 1847, 2022/08
The orientation and motion of reactants play important roles in reactions. The small rotational excitations involved render the reactants susceptible to dynamical steering, making direct comparison between experiment and theory rather challenging. Using space quantized molecular beams, we directly probe the (polar and azimuthal) orientation dependence of O
chemisorption on Cu
and Cu
Au. We observe polar and azimuthal anisotropies on both surfaces. Chemisorption proceeds rather favorably with the O-O bond axis oriented parallel (
perpendicular) to the surface, and also rather favorably with the O-O bond axis oriented along ![$$[001]$$](/search/images/ERNTAMBRLUSA.gif)
( along ![$$[bar{1}10]$$](/search/images/ERNVYYTBOJ3TC5JRGBOSI.gif)
). The presence of Au hinders the surface from further oxidation, introducing a higher activation barrier to chemisorption, and rendering an almost negligible azimuthal anisotropy. The presence of Au also prevents cartwheel-like rotating O from further reactions.
圓谷 志郎; 倉橋 光紀*; Sun, X.*; 山内 泰*
Carbon, 61, p.134 - 139, 2013/09
被引用回数：17 パーセンタイル：49.12(Chemistry, Physical)The spin-resolved electronic structure of graphene on Ni(111) was investigated using spin-polarized metastable deexcitation spectroscopy (SPMDS). Graphene was grown epitaxially on a Ni(111) single-crystalline surface using the ultra high vacuum chemical vapor deposition technique with benzene vapor as a precursor. At 50 L (5
10
Torr sec), a single epitaxial layer of graphene was formed, but no further growth was observed at higher exposure. The spin-summed spectrum of graphene/Ni(111) had a new peak at the Fermi level and three weak features corresponding to the molecular orbitals of graphene. Spin asymmetry analysis of the SPMDS spectra revealed that the spin polarization of the electronic states shown by the new peak was parallel to the majority spin of the Ni substrate. The appearance and spin polarization of the new electronic states are discussed in terms of the hybridization of graphene pi orbitals and Ni d orbitals.
圓谷 志郎; 大伴 真名歩; 倉橋 光紀*; 松本 吉弘; Avramov, P.; 楢本 洋*; 境 誠司; 山内 泰*
no journal, ,
Graphene attracts much attention as the most promising material for realizing molecular spintronic devices. In the devices, the control of the spin injection/detection processes at the interface between graphene and ferromagnetic metal (FM) electrodes are crucial for the device operation and thus the elucidations of the electronic structures at the graphene/FM interface including the spin polarization in graphene is indispensable to the designing spintronic devices. In this study, the spin-polarized electronic structure of graphene on the FM surfaces is investigated by spin-polarized metastable deexcitation spectroscopy (SPMDS). The SPMDS measurements indicated that new electronic states caused by splitting and mixing of the graphene 
-orbitals and the substrate states appeared around the Fermi energy. Spin asymmetry analysis of the SPMDS spectra revealed that the spin polarization in which majority spin is dominant was induced in the new electronic states at around the Fermi energy.
津田 泰孝; Gueriba, J. S.*; 植田 寛和; Dio, W. A.*; 倉橋 光紀*; 岡田 美智雄*
no journal, ,
The interaction of O with various metal surfaces induces changes in its chemical stability and reactivity. And the ability to control such processes bears on the chemical economy. Alloying of pristine metals provides one of the simplest and oldest way to do so. Unraveling the stereochemistry of the processes involved would be imperative for understanding the mechanisms behind of these interactions. The dynamics of reactant molecules (esp., the orientation and the movement of molecules in 3D space) plays an important role in reactions. The small rotational energy excitations involved (ca. less than a few meV) render the reactants susceptible to dynamical steering. This makes direct comparison with theory rather challenging. To directly probe and observe the (polar and azimuthal) orientation dependence of O adsorption on Cu(110) and CuAu(110), we prepared space quantized O molecular beams by sorting the quantum states of the O via Richtungsquantelung (space quantization, as first introduced by the 1922 Stern-Gerlach experiment). We found that chemisorption proceeded rather favorably with the O-O bond axis oriented parallel (vs. perpendicular) to the surface, and also for O-O bond axis oriented along [001] (vs. along [-110]). Alloying with Au introduced a higher activation barrier to chemisorption. This hinders the surface from further oxidation, and azimuthal anisotropy becomes almost negligible. The presence of Au also prevented cartwheel-like rotating O from further reactions.
