Origin of the common ordering structure in cubic rare-earth (R) hexaborides RB6 is ascribed to an RKKY polarization connecting different pockets of the conduction band. In order to account for the band structure common to RB6, a tight-binding model is used which reproduces the Fermi surface reasonably well. The model includes 2p t2u molecular orbitals for each B6 cluster and 5d eg orbitals for each rare-earth ion. The resultant intersite interaction I(q) gives rise to a broad maximum around q = (1/4,1/4,1/2) in the Brillouin zone, provided both 2p and 5d components of the conduction band participate in the exchange interaction. This wave number corresponds to the ordering pattern in GdB6 and some other rare-earth hexaborides.
- Interpocket polarization
- RKKY interaction
- Rare-earth hexaborides
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering