No abstract available

[en] The principles of the analysis by MeV Rutherford backscattering are presented. The application of the technique to the study of the composition and structure of monocrystalline surfaces is described. The advantages (quantitativity, high sensitivity to surface atomic displacements) and limits of the method are indicated

[en] The principles of the analysis by MeV Rutherford backscattering are presented. The applications of the technique to the study of the composition and structure of monocrystalline surfaces are described. The advantages (quantitativity, high sensitivity to surface atomic displacements) and limits of the method are indicated

No abstract available

No abstract available

[en] In order to produce thin films of crystalline V₂O₅, vanadium metal was thermally oxidised at 500 deg. C under oxygen pressures between 250 and 1000 mbar for 1-5 min. The oxide films were characterised by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). The lithium intercalation performance of the oxide films was investigated by cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS). It was shown that the composition, the crystallinity and the related lithium intercalation properties of the thin oxide films were critically dependent on the oxidation conditions. The formation of crystalline V₂O₅ films was stimulated by higher oxygen pressure and longer oxidation time. Exposure for 5 min at 750 mbar O₂ at 500 deg. C resulted in a surface oxide film composed of V₂O_5, and consisting of crystallites up to 200 nm in lateral size. The thickness of the layer was about 100 nm. This V₂O₅ oxide film was found to have good cycling performance in a potential window between 3.8 and 2.8 V, with a stable capacity of 117 ± 10 mAh/g at an applied current density of 3.4 μA/cm². The diffusion coefficients corresponding to the two plateaus at 3.4 and 3.2 V were determined from the impedance measurements to (5.2 and 3.0) x 10^-13 cm² s^-1, respectively. Beneath the V₂O₅ layer, lower oxides (mainly VO₂) were found close to the metal. At lower oxygen pressure and shorter exposure times, the oxide films were less crystalline and the amount of V⁴⁺ increased in the surface oxide film, as revealed by XPS. At intermediate oxygen pressures and exposure times a mixture of crystalline V₂O₅ and V₆O₁₃ was found in the oxide film