Mechanical Modulation of Colossal Magnetoresistance in Flexible Epitaxial Perovskite Manganite

Heteroepitaxially flexible oxide systems have been intensely developed and considered as the most promising materials for leading the creation of next-generation flexible electronic devices. Among them, perovskite manganites have attracted significant attention with their abundant and novel properties such as colossal magnetoresistance (CMR) and metal-insulator transition. However, the requirement of high quality samples hampers this field, not to mention the advanced nanoengineering. In this study, fluorophlogopite mica (F-mica) is selected as a flexible substrate to fabricate heteroepitaxial Pr_0.5Ca_0.5MnO₃ (PCMO) with a nanocolumn structure. Through a precise control of thickness, different morphologies are realized to manipulate the magnetotransport properties (reduction of melting field). Moreover, thanks to the excellent flexibility of F-mica, mechanical modulation of CMR (≈1000%) can be achieved in different flex modes while the magnetic properties remain unaffected. Detailed bending tests are performed to study the behavior of resistive change (≈30%). Through the combination of high flexibility, high quality PCMO, and well-designed nanocolumn structure, the study exhibits the significant controllability of CMR via mechanical bending, and manifests the potential of such a heteroepitaxially flexible oxide system which can be applied on flexible magnetoresistive devices and sensors.