Electronic Structures for Alkaline-Earth Filled Skutterudite Antimonides

The band structures are calculated for the paramagnetic AT(4)Sb(12) (A = Ca, Sr, Ba; T = Fe, Ru, Os) by using an FLAPW method. The calculated densities of states at the Fermi level for T = Fe are larger than those for T = Ru and Os and about a half of them results from the Fe-d partial density of states. For ARu(4)Sb(12) with A = Sr and Ba, the Ru-d partial density of states decreases drastically at the Fermi level consistent with the observed Sommerfeld coefficients. The stable ferromagnetic ground state for AFe(4)Sb(12) with A = Na, Ca, Sr, Ba and La has been obtained.