Hydrogen Adsorption at Nb(100): Photoemission Evidence of Two-Stage Exchange Involving Subsurface States

摘要

Temperature dependent properties of electronic states resulting from hydrogen adsorption of Nb(100) surfaces have been studied by photoemission spectroscopy using synchrotron radiation. The most prominent hydrogen induced feature in photoemission spectra exhibits a temperature dependence that requires contributions from two distinct states. Analysis of the photon energy dependent cross section of the hydrogen induced features suggests that hydrogen chemisorption sites are located below the surface. These results have important consequences for kinetic models that attempt to account for hydrogen uptake by Nb. Keywords: Surface chemistry, Structure, Electronics properties, Surfaces, Niobium, Reprints. (MJM)