Half-metallic antiferromagnetic double perovskites: LaAVRuO(6) (A=Ca, Sr, and Ba)

Abstract

Based on the theoretical exploration of electronic structures, we propose that the ordered double perovskites LaAVRuO(6) and LaVO3/ARuO(3) (001) superlattice (A=Ca, Sr, and Ba) are strong candidates for half-metallic (HM) antiferromagnets (AFM's). We have shown that the HM-AFM nature in LaAVRuO(6) is very robust regardless of (i) divalent ion replacement at A sites, (ii) oxygen site relaxation, (iii) the inclusion of the Coulomb correlation, and (iv) cation disorder. A type of the double exchange interaction is expected to be responsible for the half-metallicity and the antiferromagnetism in these systems.