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Author Lebedev, Vladimir S. ♦ Vitukhnovsky, Alexey G. ♦ Medvedev, A. S. ♦ Vasil'ev, D. N. ♦ Chubich, D. A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ABSORPTION SPECTRA ♦ COMPOSITE MATERIALS ♦ CROSS SECTIONS ♦ CRYSTAL STRUCTURE ♦ CYANINE DYES ♦ DIELECTRIC MATERIALS ♦ ELECTRON DIFFRACTION ♦ EXCITATION ♦ EXPERIMENTAL DATA ♦ GOLD ♦ KEV RANGE ♦ KRAMERS-KRONIG CORRELATION ♦ NANOSTRUCTURES ♦ OPTICAL PROPERTIES ♦ PARTICLES ♦ PEAKS ♦ POLARIZABILITY ♦ RESONANCE ♦ SILVER ♦ SPHERES ♦ SPHERICAL CONFIGURATION ♦ TRANSMISSION ELECTRON MICROSCOPY ♦ COHERENT SCATTERING ♦ CONFIGURATION ♦ CORRELATIONS ♦ DATA ♦ DIFFRACTION ♦ DYES ♦ ELECTRICAL PROPERTIES ♦ ELECTRON MICROSCOPY ♦ ELEMENTS ♦ ENERGY RANGE ♦ ENERGY-LEVEL TRANSITIONS ♦ INFORMATION ♦ MATERIALS ♦ METALS ♦ MICROSCOPY ♦ NUMERICAL DATA ♦ PHYSICAL PROPERTIES ♦ SCATTERING ♦ SPECTRA ♦ TRANSITION ELEMENTS
Abstract We report experimental and theoretical studies of the optical properties of composite nanoparticles consisting of a noble-metal (Ag or Au) core and a cyanine dye J-aggregate shell. Using transmission electron microscopy, the particles have been shown to be spherical in shape and 4 - 10 nm in size. The crystal structure of their core has been determined by 1-keV electron diffraction. The absorption spectra of such nanoparticles in aqueous suspension show two peaks, one dueto the plasmon resonance in the metallic core, and the other to electronic excitations in the J-aggregate shell. These results are interpreted in a model based on the expression for the absorption cross section of small particles, using polarisability calculations for two concentric spheres with allowance for the size effect on the dielectric function of the metallic core. The dielectric function of the J-aggregates is derived from experimental data using Kramers - Kronig relations. The shape and position of the peaks in the absorption spectra of the hybrid nanoparticles are strongly dependent ontheir geometry and the optical properties of the core and shell materials. This offers the possibility of controlling the optical properties of composite materials based on such nanoparticles. (nanostructures)
ISSN 10637818
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-05-26
Publisher Place United States
Journal Quantum Electronics
Volume Number 40
Issue Number 3


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