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Full-Text Articles in Physics

Size-Driven Domain Reorientation In Hydrothermally Derived Lead Titanate Nanoparticles, Zhiyuan Ye, Elliot B. Slamovich, Alexander H. King Mar 2005

Size-Driven Domain Reorientation In Hydrothermally Derived Lead Titanate Nanoparticles, Zhiyuan Ye, Elliot B. Slamovich, Alexander H. King

Alexander H. King

High-resolution transmission electron microscopy studies of hydrothermally derived platelike lead titanate nanoparticles reveal that below a critical size of approximately 70 nm, the single ferroelectric domain polarization axis reorients from perpendicular to parallel to the plate. We suggest that during particle growth, ions in the hydrothermal processing medium compensate for the ferroelectric depolarization energy. When the processing medium is removed by washing and drying, single domain nanoparticles minimize their depolarization energy by c-axis flipping.


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 Jan 2005

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 …


Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina Othon, Fred Bateman, Stephen Ducharme Dec 2004

Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina Othon, Fred Bateman, Stephen Ducharme

Christina M Othon

The 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 …