Secondary ion mass spectrometry, x-ray photoelectron spectroscopy, electron energy-loss spectroscopy, x-ray diffraction, transmission electron microscopy, and 15N hydrogen profiling have been used to characterize rf sputter-deposited tin oxide thin films (1500-2500Å) before and after immersion in aqueous solutions to determine the extent of film hydration and ion exchange actlvity. The results support a model in which the tin oxide film is comprised of microcrystalline, colloidlike particles or grains (200-300Å), the ion exchange sites being located on the hydroxylated grain surfaces. The uptake of Na+ in the bulk film increases sharply at a pH = 3-5 corresponding to literature values for the isoelectric point of Sn02.
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|State||Published - Jul 1 1987|