Imaging the internal electronic structure of a surface adsorbate with low energy ions.
Time-of-flight spectra were collected for 2.5 keV 7Li+ backscattered from Fe surfaces covered with submonolayers of iodine. Li singly scattered from the adatoms has a consistently larger neutral fraction than for scattering from the substrate, implying a region of positive charge atop the iodine. The neutral fraction decreases for off-normal exit angles, indicating a nonuniform charge distribution around the polarizable adsorbates. This demonstrates that ion scattering can image the internal electronic structure of an adatom and provides an explanation for anomalous work function changes.
Yarmoff
Jory A
JA
Department of Physics, University of California, Riverside, CA 92521, USA. yarmoff@ucr.edu
Yang
Ye
Y
Sroubek
Zdenek
Z