Electronic Structure of Divalent Hexaborides

Great interest in the divalent hexaborides has been generated recently by the discovery of high Curie temperature weak-moment ferromagnetism (FM) in La-doped CaB6 [1] and by exotic theoretical models to explain the unusual magnetism, e.g. that it represents the ground state of a dilute electron gas [2] or of a doped excitonic insulator [3]. The starting point of most thinkin