Stabilization of a honeycomb lattice of IrO6 octahedra by formation of ilmenite-type superlattices in MnTiO3

Abstract

In quantum spin liquid research, thin films are an attractive arena that enables the control of magnetic interactions via epitaxial strain and two-dimensionality, which are absent in bulk crystals. Here, as a promising candidate for the development of quantum spin liquids in thin films, we propose a robust ilmenite-type oxide with a honeycomb lattice of edge-sharing IrO6 octahedra artificially stabilised by superlattice formation using the ilmenite-type antiferromagnetic oxide MnTiO3. Stabilised sub-unit-cell-thick Mn–Ir–O layers are isostructural to MnTiO3 and have an atomic arrangement corresponding to ilmenite-type MnIrO3. By performing spin Hall magnetoresistance measurements, we observe that antiferromagnetic ordering in the ilmenite Mn sublattice is suppressed by modified magnetic interactions in the MnO6 planes via the IrO6 planes. These findings contribute to the development of two-dimensional Kitaev candidate materials, accelerating the discovery of exotic physics and applications specific to quantum spin liquids.