Development of multiferroic polymer nanocomposite from PVDF and (Bi_0.5Ba_0.25Sr_0.25)(Fe_0.5Ti_0.5)O₃

Thin films of some polymer–ceramics multiferroic nanocomposites (in 0–3 connectivity) of compositions (1 − x)PVDF–x((Bi_0.5Ba_0.25Sr_0.25)(Fe_0.5Ti_0.5)O₃ (x = 0.05,0.1,0.15)) have been prepared using a standard solution casting method. The basic structure and surface morphology of the materials were studied using X-ray diffraction and scanning electron microscopy technique respectively. Structural investigation confirms the presence of polymeric electro active β-phase of matrix (PVDF) and nano filler perovskite phase of the incorporated nano-ceramics. The high resolution transmission electron micrograph of the prepared nano-ceramic thin film composite has shown distinct and uniformly distributed particles (with less agglomeration). This has been observed in SEM micrographs also. The flexible nano-composites fabricated with polymer (PVDF), bismuth ferrite (BiFeO₃) and ferroelectric (BST) exhibit high dielectric constant and low tangent loss. The electric response investigated by impedance spectroscopy technique in terms of electric circuit has provided some interesting results on contributions of grain and grain boundary in the restive characteristics of the composites. The study of ac conductivity as a function of frequency obeys Jonscher’s power law. The experimentally obtained first order magnetoelectric coefficient (α_ME) is found to encouraging for multifunctional application. The improved conductivity and dielectric properties suggest some promising applications in the embedded capacitors.