Search

Rb3C60 single-crystal thin films were prepared on the cleaved (111) surface of C60 single crystal. The photoemission spectrum line shapes of the lowest unoccupied molecular orbital (LUMO) derived band at room temperature and 150 K were established by synchrotron radiation photoemission spectrum measurements. The density of states near the Fermi level was distinctly affected by temperature. No less than six sub-peaks of the LUMO band were observed even at room temperature. The existence of so many sub-peaks offered the opportunities to analyse in more detail the orientational structure and the electron-Boson interactions of the narrow-band metallic Rb3C60.

Electron band structure of C60 single crystal has been investigated using synchrotron radiation. On the cleaved (111) surface of the C60 single crystal the angle-resolved ultraviolet photoelectron spectra were measured at normal emission with varying photon energy from 12.7 to 28.2 eV. The valence band dispersions in L-Γ-L direction were successfully observed. The dispersions are 0.14 and 0.17 eV for the highest occupied molecular orbitals (HOMO) and HOMO-1 derived band respectively.

Ultra-violet photoemission spectroscopy measurements for CO adsorption on the (2×2)-Cs precovered Ru (0001) surface were performed. The Cs 5p (5p3/2) level (Cs state) locates at 11.3 eV in binding energy for the (2×2)-Cs overlayer on Ru (0001). Upon the CO adsorption, a new peak, which is associated with the Cs 5p state for the Cs adatoms influenced by the neighbouring CO adsorbed (the Cs+CO state), appears at the lower binding energy side of the Cs state. This new peak is at 10.8 eV for the CO saturation where the (2×2)-Cs+2CO compound layer is formed. This result gives clear evidence for local interaction of Cs and CO on the Ru (0001) surface. PACS: 73. 20. At, 82. 65. My, 68. 35. Bs

The geometric and electronic structures at the interface between iron phthalocyanine (FePc) and Si(110) surface are studied by ultraviolet photoelectron spectroscopy and density functional theory (DFT) calculation. After FePc is deposited on Si(110), the emission features are located at 2.56, 4.90, 7.90, 10.88 eV below the Fermi level for monolayer and 2.73, 4.90, 7.74, 10.52 eV below the Fermi level for multilayer. At the coverage of 1 ML, FePc molecules are adsorbed on the bridge site in a flat-lying geometry with a 2.17 A separation between the molecule and the substrate. The molecular plane is bent due to the interaction between the adsorbate and the substrate.

We present the simple designs of metamaterial absorbers which are composed of a periodic array of copper annular (or circular) patches, FR4 substrate, and copper film. With appropriate geometrical parameters, these metamaterials can provide the electric and magnetic resonances overlapping in the given frequency range, and the experiments demonstrate the absorptivities of 97.6% and 96.7% with only a single layer of the metamaterial absorber. The surface currents and field distributions of these metamaterials are discussed to look straight into the resonance mechanism. Furthermore, our numerical simulations confirm that these metamaterial absorbers could be operated at wide angles of incidence. The simple and highly symmetric structures of the metamaterial absorbers proposed would greatly accelerate the practical applications in optics and electromagnetics.