Optical and electronic properties of amorphous silicon dioxide by single and double electron spectroscopy

Abstract An investigation of the optical and electronic properties of amorphous silicon dioxide by means of a combination of reflection electron energy loss spectroscopy (REELS) and secondary electron–electron energy loss coincidence spectroscopy (SE2ELCS) is presented. Optical constants for a-SiO2 were extracted from the REELS measurements and a band gap of 9.1 eV was determined by deconvolution of multiple scattering and fitting the differential inverse inelastic mean free path with a model energy loss function (ELF). The coincidence measurements allow to determine the surface barrier height and the electron affinity was determined to be 0.8 eV. Furthermore, the coincidence measurements show that even in the case of an insulator, plasmon decay is the main mechanism for generation of secondary electrons

Influence of concentration and anion alkyl chain length on tribological properties of imidazolium sulfate ionic liquids as additives to glycerol in steel-steel contact lubrication

Commercially available ionic liquids were used as additives in the model lubricant fluid glycerol. The stability of the mixtures was controlled by measuring of turbidity. Tribological experiments have been performed on a reciprocating sliding tribometer in the boundary lubrication regime with three ionic liquid concentrations, as well as with neat glycerol and the neat ionic liquids at 100 °C. Wear and friction were measured, and the worn surfaces were examined with optical microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The results show the influence of the ionic liquid concentration and the anion alkyl chain length on the tribological behavior. Significant improvement in friction and wear reduction at low ionic liquid concentrations was detected and attributed to sulfur species in tribofilm

Investigation of TA frain boundary diffusion in copper by means of Auger electron spectroscopy

újratöltve - BIBFORM00866