Abstract
The results of detailed computations of the optical absorption in alkali metals are presented. Nettel's formalism is used to calculate the phonon-assisted processes and modifications are made to allow approximately for the Debye-Waller factor, multiphonon terms, anharmonic effects, and the "optical pseudopotential." The direct interband absorption is also incorporated, and the validity of the classical frequency dependence for the Drude absorption is discussed. Results are presented as a function of temperature, form factor, and pseudopotential coefficient . Smith's data for absorption in sodium are found to be consistent with eV. The data for potassium and rubidium are also consistent with the model but the data for cesium and lithium are not.
- Received 10 August 1972
DOI:https://doi.org/10.1103/PhysRevB.7.2348
©1973 American Physical Society