Freestanding BiFeO ₃ perovskite films enabled by novel sacrificial layers SrCoO _2.5

Abstract The microelectronics industry is increasingly seeking freestanding multiferroic materials for the next generation of devices. Bismuth ferrite (BiFeO 3 ), known for its remarkable ferroelectric and antiferromagnetic properties at room temperature, holds great promise for multifunctional applications. However, current fabrication methods depend on Sr 3 Al 2 O 6 sacrificial layers that deteriorate under ambient conditions, which limits their practical use. In this study, we showcase the exceptional qualities of strontium cobalt oxide (SrCoO 2.5 ) as an innovative sacrificial layer for BiFeO 3 . We successfully fabricated high‐quality films of both BiFeO 3 and SrCoO 2.5 using pulsed laser deposition (PLD), and we achieved freestanding BiFeO 3 films through a careful chemical etching process that ensures precise quality control. Our investigation into the solubility and stability of SrCoO 2.5 reveals its advantages over Sr 3 Al 2 O 6 , demonstrating enhanced durability while allowing long‐term preservation of SrCoO 2.5 . The resulting freestanding films exhibit excellent crystallinity and surface smoothness, paving the way for their integration into next‐generation electronic devices. This research not only advances the preparation of high‐quality freestanding BiFeO 3 but also highlights the potential of using SrCoO 2.5 as a sacrificial layer in various perovskite oxide thin films, which are suitable for sensors, actuators, and memory devices.