IPES and LEED Investigation of Ion Bombardment-Induced Damage and Thermal Recovery of the Ni(110) Surface

We have used the techniques of Inverse Photoelectron Spectroscopy (IPES) and Low Energy Electron Diffraction (LEED) to investigate ion-induced surface damage and thermal recovery on Ni(110). Ion bombardment creates surface defects which decrease the intensity of unoccupied electronic states as measured using IPES, and of diffracted electron beam spots as measured with LEED. Thermal annealing reduces these surface defects; a range of recovery temperatures demonstrates a linear dependence on the surface state intensity as a function of temperature. Isothermal annealing in the range of 350K-650K for different time periods causes the surface state intensity to reach different levels of saturation. We have modeled our results to obtain an activation energy of ~0.18eV.