On Surface Plasmon Spectrum in Noble Metal Nanoparticles - Rods and   Spheroids
  The surface plasmon oscillations spectra in noble metal nanoparticles - rods and spheroids embedded in a host matrix is analyzed theoretically. The important role of - electrons in formation of surface plasmon resonances is shown. A simple model is developed to describe the surface plasmons in nanorods. It is shown, that both for nanorods and spheroids the surface plasmon resonance wavelengths are linearly dependent on aspect ratios of these particles. The results of calculations are compared with experimental data for gold and silver particles and excellent agreement is demonstrated. 
Armen Melikyan and Hayk Minassian