UC Riverside

Low energy ion scattering (LEIS) is a technique found to be sensitive to the structural and electronic properties of metal on oxide systems. Here, LEIS is used to investigate the effect of sputtering Pt deposited on TiO2 as well as the effect of surface temperature on Au nanoclusters on SiO2. In the case of Pt/TiO2, it was found that sputtering induces a "strong metal-surface interaction" (SMSI) state, where the surface atoms become mobilized and move to cover the Pt. Previously, this state has been observed when heating the sample, but in this case the sputter beam was found to mobilize the substrate atoms instead of an elevated temperature. K+ scattering was used to examine Au/SiO2 at temperatures ranging from 100 to 300 K. It was found that the probability that an ion would be neutralized during scattering is inversely and reversibly proportional to the temperature. Finally, Na+ was used to examine Au/SiO2 after annealing to temperatures ranging from 300 to 1000 K. It was found that the neutralization probability is dependent not only upon the annealing temperature, but also whether the ion undergoes single or multiple scattering. The ratio of single scattering to multiple scattering neutralization probability may provide another tool to analyze surface evolution.