Super-flexibility in Freestanding Single-Crystal SrRuO₃ Conductive Oxide Membranes

Conductive oxides are considered to be attractive electrodes in electronic applications such as piezoelectric, energy storage, and semiconductor devices due to their good electrical conductivity and compatibility with other functional oxides. However, conductive oxides are generally brittle, which limits their applications in flexible electronic devices. Here, freestanding single-crystal SrRuO3 membranes have been prepared by etching a sacrificial layer. The prepared membranes can be buckled into sinusoidal shapes of different sizes, indicating that the membranes are super-flexible. The mechanical properties were performed on the well-strained membranes, and the Young’s modulus of the 12 nm-thick SrRuO3 membrane was found to be 34.65 GPa via the buckling method, which is approximately 21% of the bulk SrRuO3. The corresponding super-flexibility mechanism is attributed to the high defect density and small specific surface area. The SrRuO3 films maintain the resistivity before and after transferring in the range of 1.4 × 10–4 to 5.2 × 10–4 Ω cm that can be used as electrode materials. This work provides a realistic strategy for the super-flexibility transition of the single-crystal SrRuO3 conductive oxide membranes from brittleness, which paves the way for their application in flexible electronics devices.