Optical functions of the Drude model: transformation of the spectra over wide ranges of parameters

Abstract

The spectral features of the optical functions of the Drude model are investigated over wide ranges of parameters — the plasma frequency ωp of the current carriers, their transport relaxation frequency g, and the dielectric constant ε∞ due to high-energy electronic transitions in the system. The conditions are determined for: a) the square-root frequency dependence of the modulus and phase of the reflection; b) linearity of the phase θ=2ω/ωpε∞+θ0; c) the existence of a plasma reflection edge. Approximate relations are obtained which permit simplifying the analysis of optical reflection and electron characteristic energy loss data both in “good” metals and in materials with a strong temperature dependence of the electrical conductivity (semiconductors, doped and nonstoichiometric oxides, granular metal films, and amorphous alloys). The parameters of the systems of conduction electrons in Al and U2Zn17 are determined.

Combination Law for Drude–Sommerfeld's Electron Damping in Multilayer Thin Metal Films

“…Four are the main levels at which metals can be modeled: perfect conductors, dispersive materials, dissipative materials within classical Drude's model and extended Drude's model, when the carrier lifetime is frequency dependent. Drude's theory, thus, still applies in many cases to model the low‐frequency absorption domain, affording a straightforward explanation of ion core‐e − interactions by an effective e − mass and the sign of carrier charges . Modeling dielectric properties of material mixtures, however, may become a tough task.…”

“…Drude's theory, thus, still applies in many cases to model the lowfrequency absorption domain, affording a straightforward explanation of ion core-e À interactions by an effective e À mass and the sign of carrier charges. [20] Modeling dielectric properties of material mixtures, however, may become a tough task. Effective medium approximations alone may be used, [21] provided the sizes of mixing phases are smaller than the light wavelength, but are large enough to preserve the dielectric information of reference media.…”