Off-Specular Coherent and Incoherent Elastic Scattering from Cu(001) and Adsorbed Layers of CO and Xe

Abstract
Coherent and incoherent elastic scattering of He was observed from Cu(001) and adsorbed layers of CO and Xe. It is shown that specular and off-specular elastic scattering can yield insight into adsorption mechanisms at low coverages. The variation of incoherent elastic scattering with coverage shows different behavior for CO (random) and Xe (island) adsorption. A maximum appears in the incoherent elastic for CO as predicted theoretically for site adsorption.