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71.
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F. Flores R. Rincn J. Ortega F.J. García-Vidal R. Prez 《Progress in Surface Science》1993,42(1-4):281-295
A theoretical discussion of the state of the art in the field of Schottky barrier formation is presented. The thin metal layer limit is analyzed for Al and In on GaAs(110), and the adsorption sites are determined as a function of the metal coverage. Intrinsic and extrinsic charge neutrality levels are also discussed for the In-case. 相似文献
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In this paper, the role played by the excitation of surface phonons in the far infrared optical absorption of small metallic spheres is explored. We find that for frequencies ranging between 100 cm-3 and 200 cm-1 this absorption mechanism is dominating over the ones coming from considering electronic excitations or the Joule heating. 相似文献
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77.
Marcos A. P. Martins Alex F. C. Flores Rogrio A. Freitag Nilo Zanatta 《Journal of heterocyclic chemistry》1996,33(4):1223-1226
The investigation of the effect of the cyclopentane ring on the regiochemistry of the reactions of 2-acetylcyclopentanones 1a-d and β-methoxyvinyl trifluoromethyl ketone derivative 2a with hydroxylamine hydrochloride is reported. The reactions give regiospecifically the 4,5-trimethylene-4,5-dihydroisoxazoles 3a-d in good yields. 相似文献
78.
It is proposed that the X-ray intensity I at the forbidden 222 reflection is useful as an order parameter in the phase transition from a diamond-lattice semiconductor to a metal. Available X-ray data as a function of pressure on Si is shown to lend some support to the proposal. 相似文献
79.
The effects of the temperature on the highly correlated two-dimensional electron gas of a Si-111(1 × 1) surface have been analysed within a Hubbard Hamiltonian, going beyond the Hartree-Fock approximation. Our results show that a Kondo-like peak appearing at low T, disappears around 700 K; moreover, we find that the surface chemical potential shifts towards the valence band. All these results offer an explanation to recent experimental data of Yokotsuka et al. 相似文献
80.
Sum frequency generation surface vibrational spectroscopy and kinetic measurements using gas chromatography have been used to identify a reactive surface intermediate in situ during hydrogenation of benzene on a Pt(111) single crystal surface at Torr pressures. Upon adsorption at 310 K, both chemisorbed and physisorbed benzene coexist on the surface, a result which has not previously been observed. Kinetic measurements show a linear compensation effect for the production of both cyclohexane and cyclohexene. From these data the isokinetic temperature was identified and correlated to the chemisorbed benzene species, which were probed by means of vibrational spectroscopy. Additionally, chemisorbed benzene was determined to be a reactive intermediate, which is critical for hydrogenation. 相似文献