One-dimensional wrinkled SrRuO3 single-crystalline thin films with tunable strain gradients

The flexoelectric field generated by the strain gradient possesses the capability to modify and manipulate various material characteristics. However, achieving abundant and tunable strain gradients in thin films remains a formidable challenge. In this study, we successfully transferred SrRuO3 (SRO) free-standing single-crystalline films onto a flexible PDMS substrate using a water-soluble sacrificial layer. By applying prestrain to the substrate, the transferred film exhibited a modifiable one-dimensional (1D) wrinkled structure. Through the design of a 1D wrinkled structure, a strain gradient of up to 9.6×105m−1 was introduced in the SRO film. Simultaneously, we can precisely manipulate the morphology of the wrinkles and the magnitude of the strain gradient by adjusting both the thickness of the SRO film and the level of prestrain state, thereby achieving a highly stable and flexible SRO film with a substantial strain gradient. Furthermore, we investigate the impact of strain gradient on the electrical transport properties of SRO wrinkles. It is observed that the electrical conductivity of the wrinkled films is determined by the interplay between the thickness effect and the strain gradient effect. Flexible wrinkle films serve as an optimal platform for investigating fundamental strain-related phenomena, thus exhibiting immense potential in the realm of flexible electronics. locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon Physics Subject Headings (PhySH)Electrical properties of membranesFlexoelectricityMechanical deformationThin filmsEpitaxyStrain engineering