title: Confocal micro-Raman observation of nanometer thick oxide layers on metal nanoparticles.
abstract: It is shown for the first time that confocal micro-Raman spectroscopy can be used to detect metal oxide nanometer thick layers on metal nanoparticles. The measured frequencies of the observed oxide layers are shifted to lower frequencies and the line widths were asymmetrically broadened compared to Raman spectrum in bulk oxide of the metals. The effects are due to phonon confinement which occurs in materials of nanometer dimensions. Models of phonon confinement are used to estimate the thickness of the oxide layers.
authors: Department Physics, Hunter College, CUNY, 695 Park Ave., New York, NY 10021, USA.
authors: Frank J
authors: FJ
authors: Owens
authors: B
authors: B
authors: Reddingius
mesh_terms: D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D008670:Metals / Q000032:analysis / Q000737:chemistry*; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000032:analysis / Q000737:chemistry*; D010316:Particle Size; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D008670:Metals; D010087:Oxides