Accession Number : ADA315994

Title :   Finite Sized Oblate and Ortho-Prolate Metal Nanoparticles: Optical Theory and Potential as Surface Enhanced Raman Spectroscopic Substrates,

Corporate Author : COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY

Personal Author(s) : Hornyak, G. L. ; Patrissi, C. J. ; Martin, C. R.

PDF Url : ADA315994

Report Date : 30 SEP 1996

Pagination or Media Count : 6

Abstract : The relative absorption intensities of composites containing Au, Ag or Cu prolate (a>b=c), oblate (a<b=c), ortho-prolate (b>a=c) and ortho-oblate (b<a=c) nanoparticles have been modeled with the dynamical Maxwell-Garnett effective medium expression. The electric field of the light was along the b-axis of the nanoparticles in simulations. The semi-radii b for prolate=oblate particles and a for the ortho counterparts were equal to 26 nm. The results of simulations indicate that the absorptive power of the composites increased as particle shape changed from ortho-oblate -> ortho-oblate and prolate -> oblate. We found that in simulations, ortho-prolate particles provided the greatest intensity per unit volume fraction of metal. When considering particle shape only, the degree of enhancement expected from SERS substrates is approximately proportional to the intensity of absorption. We also propose a simple means of fabricating SERS substrates by means of the template synthesis method.

Descriptors :   *METALS, *OPTICAL PROPERTIES, *RAMAN SPECTROSCOPY, *SUBSTRATES, *PARTICLES, SIMULATION, OPTIMIZATION, SYNTHESIS, SHAPE, INTENSITY, ELECTRIC FIELDS, ABSORBERS(MATERIALS), ORGANIC COMPOUNDS, TEMPLATES, POWER, ABSORPTION.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE