Temperature dependence of nanosecond switching characteristics in ultrathin films of VDF/TrFE copolymer

The time domain measurements of ferroelectric polarization reversal were performed for spin-coated 42-nnvthick vinylidene fluoride/trifluoroethylene copolymer films deposited with an Au electrode. The observed fastest switching time down to -100°C is 100ns which is shorter than the dielectric relaxation time associated with crystalline dipole motions. For this fast polarization reversal, it seems as though the nuclei of polarization are generated independently to the thermal fluctuations of dipoles. However, the activation fields of this film depend on its permittivity at 10MHz. This result indicates that the faster components of dipole fluctuations cause nucleation because the dielectric relaxation times are broadly distributed.