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Full-Text Articles in Physics
Piezoelectric And Pyroelectric Properties Of Ferroelectric Langmuir-Blodgett Polymer Films, A.V. Bune, Chuanxing Zhu, Stephen Ducharme, L.M. Blinov, V.M. Fridkin, S.P. Palto, N.N. Petukhova, S.G. Yudin
Piezoelectric And Pyroelectric Properties Of Ferroelectric Langmuir-Blodgett Polymer Films, A.V. Bune, Chuanxing Zhu, Stephen Ducharme, L.M. Blinov, V.M. Fridkin, S.P. Palto, N.N. Petukhova, S.G. Yudin
Stephen Ducharme Publications
The piezoelectric and pyroelectric responses of ferroelectric Langmuir–Blodgett polymer films are less than the largest values measured with bulk films of the same composition. The films of the crystalline copolymer poly(vinylidene fluoride trifluoroethylene) fabricated by the Langmuir–Blodgett technique are 30 ML thick (15 nm) and are highly crystalline and oriented with polarization perpendicular to the film. Both piezoelectric and pyroelectric measurements show reversible ferroelectric switching. The films are suitable for use in pyroelectric infrared imaging and in piezoelectric acoustic transducers.
Effect Of Dipolar Molecules On Carrier Mobilities In Photorefractive Polymers, Arosha Goonesekera, Stephen Ducharme
Effect Of Dipolar Molecules On Carrier Mobilities In Photorefractive Polymers, Arosha Goonesekera, Stephen Ducharme
Stephen Ducharme Publications
The grating formation speed in photorefractive polymers is greatly reduced by highly polar molecules incorporated by necessity in large concentrations to produce large diffraction efficiency and two-beam energy coupling gain. The random electric fields generated by these dipoles interfere with charge transport by increasing the width of the hopping site energy distribution and thus greatly reducing the carrier mobility and the photorefractive speed. We conducted transport studies of several model systems consisting of combinations of two polymer binders, six charge transport agents (four for holes and two for electrons), and varying concentrations of two highly polar electro-optic chromophores. The results …
Influence Of Dynamical Scattering In Crystalline Poly„Vinylidene, C.N. Borca, Jaewu Choi, Shireen Adenwalla, Stephen Ducharme, Peter A. Dowben, Lee Robertson, V.M. Fridkin, S.P. Palto, N. Petukhova
Influence Of Dynamical Scattering In Crystalline Poly„Vinylidene, C.N. Borca, Jaewu Choi, Shireen Adenwalla, Stephen Ducharme, Peter A. Dowben, Lee Robertson, V.M. Fridkin, S.P. Palto, N. Petukhova
Stephen Ducharme Publications
The effective Debye temperature of poly(vinylidene fluoride-trifluoroethylene) copolymers was measured using photoemission and neutron diffraction techniques. An effective Debye temperature of 53611K is obtained from the photoemission data and 6963.5K from neutron diffraction measurements. This effective Debye temperature is a consequence of the temperature-dependent dynamic motions perpendicular to the surface of these crystalline polymer films.