Two types of B-site ordered structures of the double perovskite Y2CrMnO6: experimental identification and first-principles study

Abstract

Double perovskite generally exhibits small structure distortion induced by the expansion/contraction and tilting of the BO₆ octahedron. It is difficult to precisely determine their structures, particularly the phase with notable pseudo-symmetry structure and two or more phases with slightly different structures. In this paper, the double perovskite Y₂CrMnO₆ synthesized under high pressure was studied using scanning transmission electron microscopy and first-principles calculations. The new finding is that a rock-salt ordered structure and a layer ordered structure coexist in Y₂CrMnO₆. Similar to the Cu²⁺-based compound, this Mn³⁺-based compound is another new system with layer ordered structure. Unlike the structures of YCrO₃ and YMnO₃, the ordered structure of Y₂CrMnO₆ displays half-metal characteristics.