I have been using EPMA and thin film programs (GMRFilm, STRATAGem and now BadgerFilm) for backing out thin film compositions and thicknesses. Someone recently contacted me and mentioned that they use RBS for _very_ accurate thin film determinations and indicated that sometimes EPMA-generated thin film results (using thin film software) may not produce the “right results”. Is there anyone out there is probe land who is well versed in both RBS and EPMA-thin film analysis to give some information on this topic. In googling around for 30 minutes, I learned some, but the impression is that RBS is also “model” based and fits the observed spectra with theoretical models based upon presumed (possible) compositions; thus one question would be, how sensitive is it to differences in stoichiometries, e.g. if the client stated they were trying to generate a 1:1 stoichometry of a film on a substrate, but it actually was 1:1.5, would there be enough sensitivity in RBS to distinguish the two? John ============================= John Fournelle, Ph.D. Senior Scientist Director, Electron Probe and SEM Labs University of Wisconsin Dept of Geoscience 1215 West Dayton Street Madison, Wisconsin 53706 Cell 608-438-7480 **** JEOL Probe Users Listserver Moderator: Anette von der Handt, [log in to unmask], Electron Microprobe Lab, University of Minnesota Post a message: send your message to [log in to unmask] Unsubscribe: send "SIGNOFF PROBEUSERS" to [log in to unmask] On-line help and FAQ: http://probelab.geo.umn.edu/jeoluserlist.html *