Specific features of plasmon resonance in nanoparticles of different metals

Spectral dependences of the light extinction and absorption efficiency coefficients are calculated for silver, gold, nickel, and aluminum nanoparticles within the framework of the Mie theory. It is demonstrated that narrow plasmon bands are observed for small (with a radius of less than 50 nm) nanoparticles of noble metals, whereas broad bands in the spectral dependences of the extinction and absorption efficiencies are typical for nickel and aluminum nanoparticles. It is concluded that using spectral dependences of extinction for estimating the radius of nanoparticles is correct only for noble metals. The results are interpreted based on wavelength dependences of complex refractive indices of metals.