摘要
Flexible high-entropy relaxor ferroelectrics offer a promising route to overcome the long-standing challenges between mechanical flexibility, thermal stability, and electromechanical performance in piezoelectric applications. In this study, we demonstrate the novel van der Waals (vdW) epitaxial integration of a designed high-entropy oxide, Pb(Mg0.15Nb0.3Ti0.05Hf0.25Zr0.25)O3 (PMNTHZO), onto flexible muscovite (mica) and rigid silicon substrates. Through high-entropy engineering, these films exhibit excellent epitaxial crystallinity and a significantly enhanced breakdown electric field (> 4 MV cm−1 on silicon). By exploiting the vdW interfacial sliding on mica to decouple substrate clamping, the PMNTHZO films achieve an exceptionally large effective piezoelectric coefficient (d33, eff ≈ 118 ± 6 pm V−1). PMNTHZO maintains stable polarization switching above 250 °C and exhibits remarkable mechanical durability, surviving a bending radius of 3.5 mm for over 10,000 continuous deformation cycles. Validated by thickness-dependent analyses and fabricated micro-island structures that explicitly confirm the mitigation of the substrate clamping effect on mica, these results establish PMNTHZO as a robust, thermally stable, and highly flexible piezoelectric material, paving the way for next-generation harsh-environment MEMS and wearable sensors.
•Epitaxial high-entropy PMNTHZO films are integrated on Si and flexible mica.•Films exhibit high breakdown fields and superior thermal stability up to 250 °C via high-entropy design.•Robust mechanical flexibility with a 3.5 mm bending radius and high durability (bending cycle >10,000 times).•Flexible mica substrates mitigate clamping effects to enhance intrinsic piezoresponse.•Large piezoelectric response (d33 ≈ 124 pm V−1) is achieved.