Drude permittivity

The chemical nature of the metal appears in Equation (2.333) via the frequency-dependent permittivity emet(w), evaluated at the imaginary frequency iw. For simple metals, the Drude form is often reasonable ... 

The solvent is assumed to be a continuum of relative permittivity fir, and the ion to be a hard sphere of radius r with charge z e Na is the Avogadro number. Eq. (5-172) represents the electrostatic contraction change in volume for a mole of ions. According to the Drude-Nernst equation, electrostriction should be proportional to the square of the charge on the ions, inversely proportional to the ionic radii, and should increase in proportion to the value of l/s )/ 8si/8p), which depends on the nature of the solvent. It follows that A Ve will vary strongly in reactions where charges are created or neutralized, which, in turn, should show up as a solvent dependence of AE. ... 

The relative dielectric permittivity of plasmonic materials is negative below plasma frequency, and its dispersion is by Drude electron resonance model [298]... 

The permittivity of metals is usually modeled using a Drude-like function of the form ... 

The onset of transitions at 500 nm in gold causes the real part of the permittivity to hover around -1 in the region of 2.5-5.0 eV (250 to 500 nm). This results directly in the plasmon resonance tail that is visible in gold nanoparticles on the short wavelength side of the resonance, particularly in vacuum where the features are not washed out by solvent or surface effects [53]. This divergence of away from a simple Drude-like character causes a sharp rise in the bulk... 

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