Stability and charge transfer in the misfit compound (LaS)(SrS)0.2CrS2: Ab initio band-structure calculations

Abstract

Local-density approximation ab initio band-structure calculations have been carried out on the misfit compound (LaS)(SrS${)}_{0.2}$${\mathrm{CrS}}_{2}$. It appears that this phase can be regarded as an infinite two-dimensional intercalation compound. One electron is transferred from the LaS slab to the ${\mathrm{CrS}}_{2}$ slab. For the (LaS)(${\mathrm{La}}_{2\mathrm{/}3(1\mathrm{\ensuremath{-}}\mathrm{y})}$${\mathrm{Sr}}_{\mathrm{y}}$S${)}_{0.2}$${\mathrm{CrS}}_{2}$ derivatives Sr atoms can substitute La atoms up to y=1. This study confirms the existence of La vacancies in the nondoped compound and is consistent with the observed nonmetallic character of this phase.