Helium-atom-scattering measurements of surface-phonon dispersion curves of the C(111)-H(1×1) surface

Local layer-by-layer growth of Ni on hydrogen-terminated diamond C(111): A combined helium-atom scattering and XPS study

“…͑2͒ is not completely satisfactory. For further discussion an average coverage ⌰ Ni ͑last column in Table II͒ 18 The full width half maximum ͑FWHM͒ and the relative intensities of the R Ni peaks are similar to the inelastic features observed in the HAS-TOF spectra of close packed clean metal surfaces. 35 This observation indicates a high structural quality of the adsorbed Ni islands, in agreement with the results of the structural analysis, see Sec.…”

“…After this procedure the HAS-angular distributions closely resembled those recorded earlier for the H(1ϫ1)C(111) surface. 18 XP spectra recorded after this annealing procedure did not reveal any contaminations ͑particularly oxygen͒ above the detection limit ͑5% of a monolayer͒. Ni was removed after each deposition by taking the substrate out of the UHV chamber and then applying the polishing and cleaning procedure described above.…”

“…2͑a͔͒ reveal sharp first-order diffraction peaks at the anticipated positions, which have already been discussed in earlier work. 18,19 Due to the different corrugation amplitudes along the ͓11 0͔ and ͓112 ͔ azimuthal directions 28 the relative diffraction intensities along the ͓11 0͔ and the ͓112 ͔ directions differ by approximately one order of magnitude. The first-order diffraction peaks of the Ni covered H(1 ϫ1)C(111) surface ͓Fig.…”

“…The unique capabilities of the HAS technique, which can be equally well applied to metals, semiconductors, and insulators, to investigate structure and phonon-dynamics of diamond surfaces have been demonstrated in previous studies of clean H(1ϫ1)C(111) surfaces in this laboratory. 18,19 The paper is organized as follows. In the next section the experimental setup and sample preparation are described.…”

Low-frequency phonon dynamics of theC60(111)surface

“…24 The relative signal intensity of these peaks indicates that the surface studied has a relatively low density of defects and that the quality of the surface is comparable with other previously studied single-crystal dielectric and semiconductor surfaces. 25,26 Besides the diffuse elastic peak, each spectrum has a number of other fairly sharp peaks at positive-and negativeenergy transfers. The peaks at the positive-energy side correspond to the annihilation of single phonons, while those on the negative side are due to single phonon excitations.…”