High-Resolution Study of Low-Energy-Electron-Diffraction Threshold Effects on W(001) Surface

Abstract

The simultaneous high-energy-resolution and high-angular-resolution (15 meV, 0.8\ifmmode^\circ\else\textdegree\fi{}) measurements of the (00) beam diffracted from W(001) near 45\ifmmode^\circ\else\textdegree\fi{} incident angles are reported. Apart from the well-known surface-state resonance previously identified, new features located in the close vicinity of the ($\overline{1}0$) emergence energy are detected. They may remain undetected if one of the two high-resolution requirements is not fulfilled. The threshold effects are correlated with the ($\overline{1}0$) beam emergence by angular distribution and $I\ensuremath{-}V$ measurements, and possible interpretations are discussed.