Heteroepitaxial Hexagonal (00.1) CuFeO 2 Thin Film Grown on Cubic (001) SrTiO 3 Substrate Through Translational and Rotational Domain Matching

Heteroepitaxy of complex oxide thin films is a significant challenge when large mismatch in the lattice parameters (>8%) and difference crystallographic symmetry coexist between film substrate. Herein, heteroepitaxial growth hexagonal delafossite CuFeO2 with (00.1) orientation on cubic perovskite (001) SrTiO3 substrate through translational rotational domain matching epitaxy reported. The in-plane relationships are [11.0]//SrTiO3 [110] [2 1 ¯ .0]//SrTiO3 about 10% mismatch. 14.8 nm-thick shows high-crystalline quality full width at half maximum rocking curve 0.24° exhibits possible indirect optical bandgap 1.43 eV or direct 1.94 eV. not only model system demonstrating heteroepitaxy oxides reported, but also way to thin-film heterostructures integrating materials for functional devices opened.