Defect engineering of transport properties of SrIrO 3 films through molecular liquids immersion

Abstract The strong spin-orbital coupling and significant metal–oxygen covalency in 5 d oxides SrIrO 3 have stimulated a range of intriguing phenomena in recent years, rendering it attractive in both physics and chemistry. Modulation of SrIrO 3 properties through defect engineering is expected to further impact its most-studied spintronic and electrochemical functionalities. Here, we report that the transport properties of SrIrO 3 films can be effectively tuned by immersion in molecular liquids, which are typically considered inert toward transition metal oxides. The modulated transport is attributed to the formation of cation defects resulting from Sr leaching, facilitated by the enhanced ionic character of the Sr–O bond due to the strong Ir–O covalency. Comparative experiments with other transition metal oxides highlight the critical role of high covalency between the transition metal and ligand oxygen in driving these changes. This work demonstrates that bond covalency will offer a key to modify the lattice microstructures and physical properties in 5 d oxides via molecular liquid immersion, providing a strategy for introducing cation defects in the post-treatment, and potentially guiding the design of 5 d oxide-based catalysts or electronic devices.