Polarization switching in ultrathin polyvinylidene fluoride homopolymer ferroelectric films

ABSTRACT

Polarization switching in PVDF/P(VDF-TrFE) Langmuir-Blodgett films using Molecular Dynamic simulation method was studied. Simulations showed that the polarization switching for ultra-thin films proceeded according to intrinsic homogeneous switching mechanism Landau-Ginzburg-Devonshire. Values of coercive field are within 0.5–2.5 GV/m, which is consistent with experimental data. At high values of applied electric field and for thick samples the polarization switching corresponds to the Kolmogorov-Avrami-Ishibashi domain mechanism. Critical width begins from (3–6) nm being in line with experimental 10 nm. Obtained data describe the polarization switching in the transition from homogeneous to inhomogeneous region for ultrathin polymer ferroelectrics.

KEYWORDS:

• Ferroelectric polymers
• molecular modeling
• molecular dynamics
• polarization switching
• homogeneous and inhomogeneous switching
• critical sizes

Acknowledgments

This study was supported by the Russian Foundation for Basic Research (grants 15-01-04924 and 16-51-53017.) The authors cordially thank Jose Coutinho for help with AIMPRO codes calculations on the Blafis Linux-cluster from Physical Department of the University of Aveiro (Portugal).