Polarization Switching in Langmuir-Blodgett PVDF Copolymer Thin Films

Polarization switching kinetics of ferroelectric nanomesas of vinylidene fluoride-trifluoroethylene copolymer

“…The nucleation-type switching behavior is commonly observed with ferroelectric polymer films made by solvent spinning, 4,11-15 and with LB films made under certain conditions. 21,22,24 This is in contrast to the behavior of the thinnest LB copolymer film capacitors, which exhibit intrinsic switching dynamics not controlled by nucleation or domains. 23,24 Further study of local switching kinetics in ferroelectric thin films and nanostructures, especially including the dependence on temperature, is necessary if we are to understand the dominant mechanism and control it.…”

“…17 Samples made by Langmuir-Blodgett ͑LB͒ deposition, on the other hand, consist of a polycrystalline mosaic where the polymer chains are aligned parallel to the film plane 18,19 in crystals of irregular shape and typical lateral size of 30 nm to 50 nm. 20 Studies of switching dynamics in the LB films have shown both nucleation-limited 21,22 and nucleation-free ͑intrinsic͒ 23,24 behavior. To better understand the effects of nanoscale morphology, we have studied switching dynamics at the nanoscale in polycrystalline films 25 and nanostructures.…”

Extrinsic versus intrinsic ferroelectric switching: experimental investigations using ultra-thin PVDF Langmuir–Blodgett films

“…To investigate ferroelectric switching phenomena, a three pulse method is employed [11]. This method eliminates side effects for the same reasons the two pulse method does, as described above.…”

“…(a) The measured polarization curves and their fits due to equation (11) for different values of the applied field for the sample with a thickness of 63.8 nm. (b) The measured polarization curves and their fits due to equation (11) for different values of the applied field for the sample with a thickness of 16.3 nm.…”

“…(a) The measured polarization curves and their fits due to equation (11) for different values of the applied field for the sample with a thickness of 63.8 nm. (b) The measured polarization curves and their fits due to equation (11) for different values of the applied field for the sample with a thickness of 16.3 nm. (c) The measured polarization curves and their fit due to equation (11) for different values of the applied field for the sample with a thickness of 5.3 nm.…”