Freestanding La_0.7Sr_0.3MnO₃:NiO vertically aligned nanocomposite thin films for flexible perpendicular interfacial exchange coupling

Abstract

High-quality epitaxial growth of nanocomposite thin-films typically requires a high-temperature process on single-crystal oxide substrates, which limits their potential for flexible device integration. Here, we adopted a water-soluble Sr₃Al₂O₆ (SAO) sacrificial buffer layer to achieve a La_0.7Sr_0.3MnO₃ (LSMO):NiO freestanding nanocomposite thin film. Freestanding LSMO:NiO film has been transferred onto a flexible polymer substrate, and exhibits an exchange bias effect, and no film quality degradation has been observed after an extensive bending process. This study opens a route to fabricate high-quality freestanding nanocomposite thin films and lays a foundation towards the applications of these multifunctional nanocomposite thin films in flexible spintronic and electronic devices. Freestanding nanocomposite thin film has been obtained using a water-soluble sacrificial buffer layer method, and could be transferred to any other substrates, such as flexible substrates.