Chemical Reaction Mechanisms of Oxide Layer Formation via Oxygen Molecule at Ni(001) Surface as Observed by Synchrotron Photoemission Spectroscopy

Abstract

Chemical reaction dynamics on the oxide formation at the Ni(001) surface has been studied via two quantum beams (synchrotron radiation and supersonic molecular beam). It was revealed that NiO layers formation took place at an oxygen coverage less than 0.5 ML depending on translational energy of oxygen molecules. Although dissociative adsorption of oxygen takes place via physical adsorption at lower translational energy than 0.06 eV, direct activated adsorption occurs at higher energy. Potential energy barrier height is 0.3 eV for the first barrier and 1.6 eV for the second one, respectively.