arXiv subjects

B. Lalmi

Publications and source records attributed to B. Lalmi.

3 recordsLinked to original sources

arXiv2013

High resolution scanning tunnelling microscopy and extended x-ray-absorption fine structure study of the (533) silicide structure on Cu(001)

Using low energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and x-ray absorption spectroscopy (XAS) techniques, we have studied the first steps of silicon adsorption onto Cu (001) single crystal substrate. For low coverage (~ 0.5 ML) and after annealing at 100°C, STM images and LEED patterns reveal the formation of an ordered quasi commensurate superstructure. From a quantitative analysis of XAS data, we extract the Si-Cu distance and detail the local atomic arrangement of the structure.

cond-mat.mtrl-sci↗

arXiv2013

Formation and stability of a two-dimensional nickel silicide on Ni (111) an Auger, LEED, STM, and high-resolution photoemission Study

Using low energy electron diffraction (LEED), Auger electron spectroscopy (AES), scanning tunnelling microscopy (STM) and high resolution photo-electron spectroscopy (HR-PES) techniques we have studied the annealing effect of one silicon monolayer deposited at room temperature onto a Ni (111) substrate. The variations of the Si surface concentration, recorded by AES at 300°C and 400°C, show at the beginning a rapid Si decreasing followed by a slowing down up to a plateau equivalent to about 1/3 silicon monolayer. STM images and LEED patterns, both recorded at room temperature just after annealing, reveal the formation of an ordered hexagonal superstructure(rot3xrot3)R30°-type. From these observations and from a quantitative analysis of HR-PES data, recorded before and after annealing, we propose that the (rot3 x rot3)R30°superstructure corresponds to a two dimensional (2D) Ni2Si surface silicide.

cond-mat.mtrl-sci↗

arXiv2012

Effect of Oxygen Adsorption on the Local Properties of Epitaxial Graphene on SiC (0001)

The effect of oxygen adsorption on the local structure and electronic properties of monolayer graphene grown on SiC(0001) has been studied by means of Low Energy Electron Microscopy (LEEM), microprobe Low Energy Electron Diffraction (\muLEED) and microprobe Angle Resolved Photoemission (\muARPES). We show that the buffer layer of epitaxial graphene on SiC(0001) is partially decoupled after oxidation. The monitoring of the oxidation process demonstrates that the oxygen saturates the Si dangling bonds, breaks some Si-C bonds at the interface and intercalates the graphene layer. Accurate control over the oxidation parameters enables us to tune the charge density modulation in the layer.

cond-mat.mtrl-sci↗