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Full-Text Articles in Physics
Pyroelectric Study Of Polarization Switching In Langmuir-Blodgett Films Of Poly(Vinylidene Fluoride Trifluoroethylene), A.V. Sorokin, V.M. Fridkin, Stephen Ducharme
Pyroelectric Study Of Polarization Switching In Langmuir-Blodgett Films Of Poly(Vinylidene Fluoride Trifluoroethylene), A.V. Sorokin, V.M. Fridkin, Stephen Ducharme
Stephen Ducharme Publications
The ferroelectric switching in Langmuir-Blodgett films of poly (vinylidene fluoride trifluoroethylene) is studied. The films have a distribution of switching times several decades wide. Nearly a half of the film volume may be switched faster than 1 ms, though complete switching of a whole sample may require 100 s or more. The switching occurs through a domain nucleation and growth mechanism. The decay of polarization at zero bias is logarithmic in time, with a constant rate below 5% per decade at room temperatures. The coercive voltage may be as low as 5 V, which makes the films promising for use …
Manifestation Of A Ferroelectric Phase Transition, A. R. Geivandov, S.G. Yudin, V.M. Fridkin, Stephen Ducharme
Manifestation Of A Ferroelectric Phase Transition, A. R. Geivandov, S.G. Yudin, V.M. Fridkin, Stephen Ducharme
Stephen Ducharme Publications
Temperature dependences of the dielectric properties of ultrathin polyvinylidene fluoride films prepared using the Langmuir-Blodgett method were studied by linear and nonlinear dielectric spectroscopy. It is shown that ultrathin Langmuir films of polyvinylidene fluoride exhibit a manifestation of a first-order ferroelectric phase transition, which can be assigned to the interaction between the spontaneous polarization and the surfaces bounding the film. As the film thickness increases, the effect of the surfaces decreases and the ferroelectric phase transition shifts to high temperatures to vanish altogether when the temperature region of the transition rises above the melting point.
Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina M. Othon, F.B. Bateman, Stephen Ducharme
Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina M. Othon, F.B. Bateman, Stephen Ducharme
Stephen Ducharme Publications
he effect of irradiation on the ferroelectric properties of Langmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluoroethylene) was investigated using 1-MeV electrons for doses from 0.16 to 1.10 MGy, where 1 Gray (Gy)=100 rad. Irradiation causes a systematic decrease in the phase-transition temperature, crystallinity, and spontaneous polarization of the films. The crystallinity and spontaneous polarization of the films decreased by amounts proportional to the dose, both tending toward zero near a dose of 1.30 MGy. The ferroelectric-paraelectric phase-transition temperature, however, was only reduced by about 12%, indicating that the primary effect of irradiation was to convert a crystalline ferroelectric material to …
Switching In One Monolayer Of The Ferroelectric Polymer, Vladimir Fridkin, A. Ievlev, K. Verkhovskaya, G. Vizdrik, S. Yudin, Stephen Ducharme
Switching In One Monolayer Of The Ferroelectric Polymer, Vladimir Fridkin, A. Ievlev, K. Verkhovskaya, G. Vizdrik, S. Yudin, Stephen Ducharme
Stephen Ducharme Publications
The switching in one monolayer of ferroelectric vinylidene fluoride-trifluoroethylene copolymer P[VDF-TrFE] is observed. The kinetics of switching is well described by Landau- Khalatnikov (LK) equation.
The paper is devoted to the 75th anniversary of Prof. Lemanov’s birthday.
The Effects Of Humidity On The Dielectric Response In Ferroelectric Polymer Films Made By Langmuir-Blodgett Deposition, Kristin L. Kraemer, Alexander V. Sorokin, Christina M. Othon, Stephen Ducharme, Vladimir M. Fridkin
The Effects Of Humidity On The Dielectric Response In Ferroelectric Polymer Films Made By Langmuir-Blodgett Deposition, Kristin L. Kraemer, Alexander V. Sorokin, Christina M. Othon, Stephen Ducharme, Vladimir M. Fridkin
Stephen Ducharme Publications
No abstract provided.
Investigation Of Ferroelectricity In Newly Synthesized Nitrile Polymer Systems, Matt Poulsen, Stephen Ducharme, Alexander V. Sorokin, Sahadeva Reddy, James M. Takacs, Y. Wen, Jihee Kim, Shireen Adenwalla
Investigation Of Ferroelectricity In Newly Synthesized Nitrile Polymer Systems, Matt Poulsen, Stephen Ducharme, Alexander V. Sorokin, Sahadeva Reddy, James M. Takacs, Y. Wen, Jihee Kim, Shireen Adenwalla
Stephen Ducharme Publications
The ferroelectric and piezoelectric properties of newly synthesized polymer systems have been studied. To date PVDF and its copolymers P(VDF-TrFE) have provided the bulk of the knowledge pertaining to ferroelectricity in polymers. Recently, ultrathin ferroelectric films of P(VDF-TrFE) 70:30 have been fabricated using the Langmuir-Blodgett technique [4]. In this study, various new polymers have been synthesized by chemically altering the PVDF structure. This alteration was performed in order to enhance the amphiphilic nature of the polymer and thus improve the LB film quality and control. Various chemical groups have been used to replace the electropositive hydrogen and electronegative fluorine found …