Single-crystal-like, c -axis oriented BaTiO₃ thin films with high-performance on flexible metal templates for ferroelectric applications

Epitaxial, c -axis oriented BaTiO₃ thin films were deposited using pulsed laser ablation on flexible, polycrystalline Ni alloy tape with biaxially textured oxide buffer multilayers. The high quality of epitaxial BaTiO₃ thin films with P4mm group symmetry was confirmed by x-ray diffraction. The microscopic ferroelectric domain structure and the piezoelectric domain switching in these films were confirmed via spatially resolved piezoresponse mapping and local hysteresis loops. Macroscopic measurements demonstrate that the films have well-saturated hysteresis loops with a high remanent polarization of ∼11.5 μC/ cm2. Such high-quality, single-crystal-like BaTiO₃ films on low-cost, polycrystalline, flexible Ni alloy substrates are attractive for applications in flexible lead-free ferroelectric devices.