Change in the nature of the Ni diffusion mechanism on the Si(111) surface with adsorption of Co atoms

The diffusion of Ni on a Si (111) surface is investigated by LEED and Auger electron spectroscopy. It is found that, in contrast to the process on the initially clean Si (111)−7×7 surface, on Si (111) surfaces with submonolayer Co coverages the nature of the Ni transport mechanism changes at a temperature of about 750 °C, and the Ni surface diffusion coefficients increase sharply below this temperature. Pis’ma Zh. éksp. Teor. Fiz. 66, No. 9, 611–614 (10 November 1997)     

Formation of strontium atomic chains on the singular and stepped Si(111) surfaces

The surface structures 3 × 2, 5 × 2, 7 × 2, and 9 × 2 formed on the Si(111) plane during adsorption of submonolayer strontium have been investigated using scanning tunneling microscopy. The experimental data obtained are in agreement with the models of surface reconstructions proposed earlier for the structures induced by the adsorption of divalent metal atoms. An important constituent of these structures is provided by strontium atomic chains in the 〈1$ \bar 1 $ \bar 1 0〉 direction. Three types of domains of surface structures are formed on the Si(111) plane, which correspond to the rotational symmetry C ₃ of the surface under consideration. The reduction of the symmetry of the substrate to C ₁ with the use of the stepped Si(7 7 10) surface makes it possible to form strontium atomic chains, which are oriented with respect to the substrate in a similar manner.     

Surface diffusion of Ni on Si(111) with coadsorption of Co

The effect of the coadsorption of Co and Ni on an Si(111) surface structure and on the diffusion of adsorbed atoms is investigated by low-energy electron diffraction and Auger electron spectroscopy. It is established that surface structures similar to those formed with the adsorption of Co alone are formed with the Ni and Co coadsorption on an Si(111) surface. It is found that the contribution of surface diffusion to the transport of Ni atoms is sharply higher on an Si(111) surface with submonolayer Co concentrations in the temperature range 500–750 °C than for a pure surface, where the main mechanism of Ni transport along the surface is diffusion of Ni atoms through the bulk of Si. Fiz. Tverd. Tela (St. Petersburg) 41, 1489–1494 (August 1999)     

Formation of ordered arrays of Ag nanowires and nanodots on Si(5 5 7) surface

The ordered arrays of Ag nanowires and nanodots have been grown in ultra-high vacuum on the Si(5 5 7) surface containing regular steps of three bilayer height. Formation of Ag nanostructures have been studied by scanning tunneling microscopy, low energy electron diffraction and Auger electron spectroscopy at room temperature. It was shown that a sample exposure in the vacuum before Ag growth affects the shape of the forming Ag islands. This effect is caused by oxygen adsorption on the silicon surface from the residual atmosphere in the vacuum chamber. When Ag is deposited on the clean silicon surface the islands, overlapping several (1 1 1) neighboring terraces, form. The arrays of silver nanowires elongated along steps and silver nanodots, arranged in lines parallel to the steps, can be formed on the Si(5 5 7) surface depending on the amount of adsorbed oxygen.     

Nature of contrast in Ge/Si(111) layers in scanning tunneling microscopy in the presence of Bi and Sb surfactants

It is known that the use of Bi surfactant (unlike Sb) upon the growth of Ge layers on Si(111) increases the contrast between Ge and Si atoms in a scanning tunneling microscope. This makes it possible to distinguish the Ge and Si surfaces. This effect is studied using computer simulation based on the density functional theory. To explain the observed difference between the Ge and Si layers, both structural and electronic effects are considered. The local density of electronic states, as well as the corresponding decay length to vacuum, has been calculated for each of the surfaces. The simulation results have been compared to the previous scanning tunneling microscopy data.     

Deformation of the Interatomic Bonds in the Upper Layers of the Ge(111) Surface with c(2 × 8), 7 × 7, and 5 × 5 Structures

Journal of Experimental and Theoretical Physics - The deformation of the interatomic bonds in the upper atomic layers of the Ge(111) surface with c(2 × 8), 7 × 7, and 5 × 5...     

Atomic Models of the Si(110)-5 × 8 and Ge(110)-c(10 × 8) Surfaces

Journal of Experimental and Theoretical Physics - The atomic models of the Si(110)-5 × 8 and Ge(110)-c(10 × 8) surfaces, which are based on a universal building block for the family of...     

Magnification Effects in Scanning Tunneling Microscopy: the Role of Surface Radicals

Journal of Experimental and Theoretical Physics - Scanning tunneling microscopy (STM) is a fundamental tool for determination of the surface atomic structure. However, the interpretation of high...     

Surface diffusion of Pb on clean Si surfaces

Pb diffusion on clean Si(111), (100), and (110) surfaces was studied by Auger electron spectroscopy and low energy electron diffraction in the temperature range from 100 to 300°C. It is shown that lead transport along sillicon surfaces takes place via the mechanism of solid-phase spreading with a sharp moving boundary. The temperature dependence of the Pb diffusion coefficients on Si(111), (100) and (110) surfaces have been obtained. A Si(110)-4×2-Pb surface structure has been observed for the first time.