Single-crystal high entropy perovskite oxide epitaxial films

Abstract

Examples of single-crystal epitaxial thin films of a high entropy perovskite oxide are synthesized. Pulsed laser deposition is used to grow the configurationally disordered $AB{\\mathrm{O}}_{3}$ perovskite $\\mathrm{Ba}(\\mathrm{Z}{\\mathrm{r}}_{0.2}\\mathrm{S}{\\mathrm{n}}_{0.2}\\mathrm{T}{\\mathrm{i}}_{0.2}\\mathrm{H}{\\mathrm{f}}_{0.2}\\mathrm{N}{\\mathrm{b}}_{0.2}){\\mathrm{O}}_{3}$ epitaxially on $\\mathrm{SrTi}{\\mathrm{O}}_{3}$ and MgO substrates. X-ray diffraction and scanning transmission electron microscopy demonstrate that the films are single phase with excellent crystallinity and atomically abrupt interfaces to the underlying substrates. Atomically resolved electron-energy-loss spectroscopy mapping shows a uniform and random distribution of all $B$-site cations. The ability to stabilize perovskites with this level of configurational disorder offers new possibilities for designing materials from a much broader combinatorial cation pallet while providing a fresh avenue for fundamental studies in strongly correlated quantum materials where local disorder can play a critical role in determining macroscopic properties.