We have performed ab initio calculations based on t-matrix formalism in the framework of the nearly free electron [NFE] theory to determine the electrical resistivity ρ and the thermoelectric power S of three liquid alkali metals, namely, Na, K and Rb. The present approach is primarily based on the Dreirach model that considers a shift EB between the bottom of the free electrons density-of-states (DOS) and the muffin tin zero (VMTZ). Concurrently the second model initiated by Esposito et al. that takes into account the nearly free electrons (NFE) without any gap between NFE-DOS and VMTZ has also been tested. The results ρ and S obtained from the Esposito et al. model are not consistent with experimental counterparts. A substantial improvement of ρ and S values is obtained from Dreirach model provided the temperature dependence of ρ versus energy is considered in order to reproduce the correct sign for S. This observation is presumably related to the fact that in the range between 0 and EF on the energy scale, the DOS for these metals fairly resemble those of free electrons yielding their effective valence Nc to be very close to the valence number Z but with a shift of the bottom of the band which cannot be neglected.
- Alkali metals
- Electrical transport
- t-matrix formalism
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering