Preparation of atomically clean surfaces of selected elements: A review

Rare gas (He, Ne, Ar, Kr, and Xe) scattering distributions have been measured from a tungsten (110) surface at an incidence angle of 45°. The gas temperature was 295°K, while the surface temperature varied between 375 and 1300°K. The positions of the peak maxima and the broadening of pseudospecular scattering of He and Ne correlate with the FRI models, whereas the Ar–Xe results are anomalous in that these aspects of the scattering do not correlate with either the FRI or soft‐cube models because Ar, Kr, and Xe are dominated by trapping at the surface. An estimate of the fraction of the rare gas atoms initially trapped at the surface has been made. Deuterium scattering distributions have been measured and are characterized by a relatively large diffuse fraction which is attributed to an internal excitation of the diatomic molecule rather than to trapping at the metal surface. Comparisons of these data with scattering from the (111) face of fcc crystals suggests three phenomenologically distinguishable scattering regimes, quasielastic, inelastic, and trapping dominated scattering.

Scattering of Helium, Neon, Argon, Krypton, Xenon, and Deuterium from a Tungsten (110) Surface Characterized by LEED

The characterization of surface carbides of tungsten

Auger spectroscopy explores the electronic energy levels in atoms and solids. as an analytical technique, it has been applied to investigations of the first few atom layers of surfaces. the term “Auger process” has come to denote any electron de-excitation in which the de-excitation energy is transferred to a second electron, the “Auger electron.” Because of the discrete nature of most electronic energy levels, Auger electrons are best characterized by their energies. Therefore, the Auger process can be analyzed by measuring the energy distribution N(E) of Auger electrons, where E is the electron energy. Experimental N(E) curves contain much more information than just those concerning the Auger process, and this extra information adds greatly to the usefulness of the data. Low-energy Auger electrons (≲ 1 keV) can escape from only the first several atom layers of a surface because they are strongly absorbed by even a monolayer of atoms. This property gives Auger spectroscopy its high surface sensitivity.

Analytical Auger Electron Spectroscopy

http://www-old.mpi-halle.mpg.de/mpi/publi/pdf/9056_10.pdf

Jar-Mo Chen

Papers

Ditungsten carbide overlayer on w(112).