AVS 53rd International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThA

Paper AS-ThA6
Ion Sputtering and the Static Limit for Nanoparticles

Thursday, November 16, 2006, 3:40 pm, Room 2005

Session: Combined Methods or Multiple Methods
Presenter: D.J. Gaspar, PNNL
Authors: D.J. Gaspar, PNNL
Z. Zhu, PNNL
A.S. Lea, PNNL
D.R. Baer, PNNL
M.H. Engelhard, PNNL
Correspondent: Click to Email
The behavior of nanomaterials varies in many cases from that observed for bulk materials. During the course of studies on several types of particles and nanostructured materials, we have observed evidence that the extent of damage and material removal rates due to ion sputtering may be significantly different than for continuous films or bulk forms of similar materials.@footnote 1,2@ This presentation will review our efforts to quantify the sputter and damage rates for some particle and nanomaterial systems, including salt particles, iron oxide, titania and ceria nanoparticles and nanoporous silica films. Additionally, we have attempted to correlate measurement of SIMS damage cross-sections in measurements of titania nanoparticles with other measurements of particle structure and chemistry, including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). For the data presented here, material removal rates are monitored directly by profilometry, and indirectly by TOF-SIMS, XPS and Auger Electron Spectroscopy (AES). For large aggregates of nanoparticles, TOF-SIMS spectra appear the same as bulk materials. We have extended these measurements to TiO@sub 2@ nanoparticles dispersed by chemical attachment to self-assembled monolayers. We suggest the contributions of geometric factors and energy transfer modified by nanoscale features contribute to observed variations in sputter rates. We examine the relationship of our observations to theoretical efforts including the theory of Bradley and Harper@footnote 3@ and Monte Carlo simulations of nanoscale effects on sputtering.@footnote 4@ @FootnoteText@ @footnote 1@D.J. Gaspar, et al., Surf. Interface Anal., 37 (2005) 417-423.@footnote 2@Baer, D.R., et al., J. Surf. Anal., 12 (2005) In press.@footnote 3@Bradley, R.M. and J.E. Harper, J. Vac. Sci. Technol. A 6 (1988) 2390.@footnote 4@Jurac, S., et al., Astrophys. J., 503 (1998) 247-252.