Aaron Fleet, Darren Dale, Y. Suzuki, J.D. Brook
Cornell University
Abstract:
The plume of
material ablated from a target in PLD contains a distribution of
neutral, ionic, and polyatomic species, with energies of up to 100eV.
Previous growth studies have described the growing film according to
standard statistical thermodynamics, and have interpreted experimental
results in the context of well-known growth modes. In contrast, our
group previously demonstrated the activation of energetic atomistic
mechanisms during hyperthermal ion epitaxy. In particular, incident
ions with energies near 20eV can insert themselves near terrace edges
during Cu homoepitaxy, given sufficient surface step-edge density.
We are investigating whether similar processes occur during PLD of perovskite materials. During SrTiO3 homoepitaxy, we diffract synchrotron x-rays off of the film, with ms time resolution. We observe rapid changes in the x-ray intensity following laser pulses at varying surface coverage, suggesting the influence of step edge density on rapid incorporation of ablated material during PLD. This work is supported by the Cornell Center for Materials Research, under National Science Foundation Grant No. DMR-0079992, and uses facilities at the Cornell High Energy Synchrotron Source, NSF Grant No. DMR-9713424.
2008 Run
Nov 19th - Dec 22nd
