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The Si/Ag(110) interface is attracting increasing interest since the recent claim that the one-dimensional (1D) nanostructures formed at this surface would be silicene nanoribbons. Lately, the synthesis of multilayer silicene nanoribbons was reported as well. In this paper, we report on the scanning tunneling microscopy, low-energy electron diffraction, and density functional theory study of the 1D nanostructures forming on Ag(110) upon Si deposition at temperatures above 460 K. Two different kinds of nanostructures are here described: nanodikes and nanotrenches, respectively protruding from and engraved on the Ag(110) substrate. The first kind of structure was recently reported to be constituted by multistacks of silicene nanoribbons. We show here that nanodikes and nanotrenches are the result of silver faceting stabilized by silicon atoms. Indeed, such nanostructures share the very same facet crystallographic features, namely inclination and reconstruction: the top and base parts are Ag(110) planes, while their sides are Ag(221) and Ag(22$\overline{1}$) facets stabilized by Si atoms. Finally, density functional theory calculations suggest that Si atoms may substitute Ag atoms in such facets, casting doubts on the usual assumption that Ag is a suitable substrate for silicene growth because it is inert against silicon.

An Sb/Si(lll)root 3x root3 surface has been studied by high-resolution core-level spectroscopy. All the components of the Si 2p core level related to the clean surface have disappeared, and one strong Sb-induced component could be identified at a binding energy +0.13 eV with respect to the bulk peak. Such a component is mainly due to charge transfer between Si atoms at the top layer and Sb trimers. Two more small components are observed: one at +0.29 eV, due to Sb atoms residing at a different position, and one at -0.14 eV, due to local disorder. On the Si 2p core level taken in bulk sensitive mode, we found a very narrow bulk component with a total full width at half maximum of 130 meV at T=100 K.

The surface atomic structure of the molecular-beam epitaxy prepared As-rich InAs(100) $(2\ifmmode\times\else\texttimes\fi{}4)$ reconstruction has been solved by synchrotron radiation surface x-ray diffraction. Analysis of a large set of nonequivalent in-plane diffraction peaks and seven out-of-plane rods yields the so-called $\ensuremath{\beta}2\ensuremath{-}(2\ifmmode\times\else\texttimes\fi{}4)$ model, a now recognized model for the As-rich GaAs(100) $(2\ifmmode\times\else\texttimes\fi{}4)$ structure. The structure comprises two As dimers in the top layer and one As dimer in the third layer below the first incomplete In layer.

A $\mathrm{S}\mathrm{b}/\mathrm{S}\mathrm{i}(110)2\ifmmode\times\else\texttimes\fi{}3$ surface has been studied by high-resolution core-level spectroscopy. All the components of the Si $2p$ core level related to the clean surface have disappeared and one strong Sb-induced component could be identified at a binding energy +0.24 eV with respect to the bulk peak. Such component is suggested to be mainly due to the charge transfer between Si and Sb atoms at the top layer. A small component, probably due to local disorder, is present on the high kinetic energy side at -0.12 eV. The Sb $4d$ core-level spectrum is well represented by one doublet, characteristic of Sb atoms adsorbed in a unique environment.

Surface differential reflectivity measurements have been carried out for a cleaved CdTe(110) surface. A broad structure centered around 3.5 eV has been found and been deconvolved into three main spectral features at 2.9, 3.5, and 3.9 eV. Our analysis ascribes these peaks to optical transitions at the \ensuremath{\Gamma}, X, and X' points of the surface Brillouin zone, respectively. The oxidation process of the surface was analyzed and the sticking coefficient of excited molecular oxygen was estimated.

Scanning tunneling microscopy (STM) has been used to study the $\mathrm{S}\mathrm{b}/\mathrm{S}\mathrm{i}(110) 2\ifmmode\times\else\texttimes\fi{}3$ surface at room temperature. The STM filled-state image shows the presence of four protrusions per unit cell while the empty-state one presents two broader protrusions. These results are consistent with single Sb adatoms saturating three Si dangling bonds.

Our photoemission spectroscopy results clearly demonstrate that symmetry breakdown in atomic arrangement brings about a lift of degeneracy in electronic states, leading to settle a long-standing controversy on a surface superstructure. We provide unambiguous evidences that Si(111)A33A3-Ag has the inequivalent triangle structure ~IET!, excluding a long-lived honeycomb-chained triangle model. We also give critical experimental proof that the surface exhibits a disorder-order phase transition by cooling; the thermally fluctuating IET structure is frozen.

The early stages of Sb films deposited at room temperature on Si(100)2×1 surfaces have been investigated by angle-integrated and angle-resolved Auger spectroscopy. A comparison between the experimental results and the predictions of simple deposition models indicates that the growth of the Sb film proceeds by island formation. Without any annealing, a uniform overlayer never develops up to films 4 nm thick

Results of surface differential reflectivity with polarized light at photon energies above the gap are presented for Si(111)-(2\ifmmode\times\else\texttimes\fi{}1) single-domain surfaces. They show an anisotropic behavior in the 2\char21{}3.5-eV range with a maximum when the electric vector is parallel to the [2\ifmmode\bar\else\textasciimacron\fi{}11] direction of the reconstructed surface. The results are compared with those previously reported for energies below the gap and are interpreted in terms of transitions involving dangling-bond bands at different points of the surface Brillouin zone, in the framework of the Pandey model of the surface.