Review of Work on the Theory of Electromagnetic Wave Absorption by Ideal and Nonideal Crystal Lattices

Abstract

Elementary theory gives as the complex permittivity of an ionic crystal

$$ \varepsilon (\omega ) = {\varepsilon _\infty } + ({\varepsilon _0} - {\varepsilon _\infty })/\left[ {1 - {{\left( {\frac{\omega }{{{\omega _0}}}} \right)}^2} - i\left( {\frac{\omega }{{{\omega _0}}}} \right)\frac{\Upsilon }{\omega }} \right],$$

((1.1))

where ε₀ and ε_∞ are the static and high-frequency permittivities, ?₀ the frequency of transverse long-wave optical vibrations of the ions (the dispersion frequency), and γ a constant describing the damping of the dispersion vibration, whose value in this theory is obtained from experiment.