Characterization of charge-ordering domains in epitaxial AlV2O4 films

Characterize the existence and structure of the domains produced by the poorly understood (1/3, 1/3, 1/3)pc superlattice in epitaxial AlV2O4 thin films.

Background

The paper reports epitaxial AlV2O4 thin films that reproduce the known charge-ordering behavior of bulk AlV2O4, including the cubic-to-rhombohedral transition and the established (1/2, 1/2, 1/2)pc superlattice. In addition, the authors observe previously unknown (1/3, 1/3, 1/3)pc superlattice spots propagating toward the out-of-plane direction.

The authors explain that cubic lattice twinning and the cubic-to-rhombohedral transition can generate multiple structural domains. Because the nature of the (1/3, 1/3, 1/3)pc superlattice is not well understood, the existence and structure of the associated domains remain unresolved, making their characterization an explicit open problem.