Combinatorial sputter synthesis of single-phase La(XYZ)O$_{3\pm\sigma}$ perovskite thin film libraries: a new platform for materials discovery

Compositionally complex perovskites provide the opportunity to develop stable and active catalysts for electrochemical applications. The challenge lies in the identification of single-phase perovskites with optimized composition for high electrical conductivity. Leveraging a recently discovered effect of self-organized thin film growth during reactive sputtering, La-Co-Mn-O and La-Co-Mn-Fe-O perovskite (ABO3) thin film materials libraries are synthesized. These show phase-pure La-perovskites over a wide range of chemical composition variation for the B-site elements for deposition temperatures equal to or higher than 300$^\circ$C. It is demonstrated that this approach enables the discovery and tailoring of chemical compositions for desired optical bandgap and electrical conductivity, and thereby opens the path for the targeted development of e.g. new high-performance electrocatalysts.