Preparation and excellent dielectric properties of flexible Ba_0.7Sr_0.29La_0.01TiO₃ composite fiber ceramics

Ba_0.7Sr_0.29La_0.01TiO₃ (BSLT) fibers with good crystallinity were prepared by the electrospinning method, and the flexible BSLT/PVDF composite membranes were prepared by a simple papermaking process. The fiber exhibited good fiber morphology after being heat-treated to 900 °C. The composite membrane showed strong tensile strength and excellent dielectric properties. The tensile strength of the 20% PVDF composite membrane was 2.66 times that of pure BSLT membrane. Fiber membrane after compounding with PVDF maintained high dielectric constant ε_r with a small dielectric loss tanδ. It has good frequency stability in the range of 100 Hz to 100 kHz. The dielectric constant of 20% PVDF composite fiber membrane could still reach 49.5 (f = 1000 Hz). The dielectric constant and dielectric loss maintained good stability in the range of 40 to 160 °C. The dielectric constant and dielectric loss of the prepared fiber membrane possessed more stable temperature stability and frequency stability than those of barium titanate-based/organic polymer membranes prepared by other methods.