Electronic structure and charge transfer in the ternary intercalated graphite beta-KS0.25C3.
The electronic structure of the ternary intercalated graphite beta-KS(0.25)C3 is studied by means of a first-principles density functional theory approach. The nature of the partially filled bands is analyzed, and the K sublayers of the intercalate are shown to have an important contribution to the Fermi surface. This K-based contribution confers a sizable three-dimensional character to the conductivity even if considerably less than that for the related binary KC8. The electronic structure of beta-KS(0.25)C3 differs noticeably from that of the related ternary compound, KH(x)C4. The charge transfer is analyzed, and a way to evaluate it, which can be used in general for intercalated graphites, is proposed. The charge transfer per C atom in this ternary material is shown to be smaller than that in the KC8 binary compound despite a more favorable stoichiometry ratio between K and C.
Rodríguez-Fortea
Antonio
A
Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel.li Domingo s/n, 43007 Tarragona, Spain.
Rovira
Carme
C
Ordejón
Pablo
P
Hérold
Claire
C
Lagrange
Philippe
P
Canadell
Enric
E