Electronic and magnetic properties of double perovskites A(2)FeReO(6) (A = Ba, Ca)

摘要

We have studied the magnetic and electronic properties of double perovskites A(2)FeReO(6) with A = Ba and Ca using ab initio methods based on density functional theory. It has been shown that when changing Ba by Ca the system undergoes a metal-insulator transition coincidentally to a structural phase transition, even if conduction band fillings are not significantly changed. Our results suggest that only considering a quite large correlation term on the Re site could explain an insulating character for Ca2FeReO6. Instead, we found that small correlations could induce a bad metallic behavior as suggested in more recent experiments.