Reference plane for the electronic states in thin films on stepped surfaces

Abstract

The question on whether there exists a unique photoelectron reference plane for a stepped solid surface is discussed on the basis of angle-resolved photoelectron spectroscopy data for Ag films grown on Pt(997). Different step morphologies at the surface and interface, revealed by low-energy electron diffraction measurements, result in distinctly different band dispersions of the sp-like quantum well states and of the Shockley surface state. Quantum well standing waves form between the parallel optical surface and interface planes, while the surface state follows the orientation of a local plane tilted with respect to the optical surface. These findings show the connection of the photoelectron reference plane with the local morphology of a solid surface and the spatial extent of the electron wave functions.

Ocean liming effects on dissolved organic matter dynamics

“…The mechanism of DOM co-precipitation and/or physical incorporation into CaCO3 is due to the formation of insoluble calcium. This hypothesis is further supported by the observation of CaCO3 precipitation following the dissolution of hydrated lime, that was enhanced by the occurrence of nucleation surfaces as particles or solid mineral phases in the solution (Moras et al, 2021).…”