Finite Sized Oblate and Ortho-Prolate Metal Nanoparticles: Optical Theory and Potential as Surface Enhanced Raman Spectroscopic Substrates,
COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY
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The relative absorption intensities of composites containing Au, Ag or Cu prolate abc, oblate abc, ortho-prolate bac and ortho-oblate bac 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 prolateoblate 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.
- Inorganic Chemistry
- Physical Chemistry
- Atomic and Molecular Physics and Spectroscopy