Tunable polarization components and electric field induced crystallization in polyvinylidenefluoride: A piezo polymer

Abstract

Polyvinylidenefluoride (PVDF) a semicrystalline pieozoelectric polymer was synthesized with varying process conditions and its ferroelectric domain orientations were studied using piezoresponse force microscope (PFM). PVDF thin films fabricated using tape casting technique with precursor solutions of varying viscosities reveal that the polarization components transform from a dominant planar to an out‐of‐plane configuration with increase in viscosity. Interestingly the planar components possessed a head to head or tail to tail kind of paired domains separated by a distance of ~ 380‐400 nm. Electrostatic energy minimization of an electrically inhomogeneous system containing similar domain arrangements as the experiments shows that the head to head and tail to tail arrangements with a minimum separation distance are more favorable than head to tail arrangements of domains. With increment of applied field, the domains grew in size and shape indicating amorphous to crystalline transformation of PVDF films. Such transformation was evident from X‐ray diffraction studies performed in‐situ in the presence of an applied electric field.