Solid-phase epitaxy of CuAlO₂ as a template layer for growth of delafossite films

Thin film growth of ABO₂ delafossites has garnered significant attention due to its attractive properties and potential applications. However, achieving high quality thin films is still an obstacle. A fundamental requirement for achieving high quality thin films relies on chemical compatibility and lattice matching substrates. Here, we report a process to engineer a template ABO₂ delafossite structure by solid-phase epitaxy of CuAlO₂ on the surface of a commercial sapphire substrate. This approach offers a promising route to growing high quality epitaxial thin films. In this talk, we will discuss the process and optimization parameters used to prepare CuAlO₂ samples and show an example of a successful epitaxial growth of highly conducting PdCrO₂ by using a CuAlO₂ template. This method provides an essential stepping-stone toward the approachability of a lattice matching template for ABO₂ heterostructures.