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University of Nebraska - Lincoln

2000

Stephen Ducharme Publications

Articles 1 - 2 of 2

Full-Text Articles in Physics

Intrinsic Ferroelectric Coercive Field, Stephen Ducharme, V.M. Fridkin, A.V. Bune, S.P. Palto, L.M. Blinov, N.N. Petukhova, S.G. Yudin Jan 2000

Intrinsic Ferroelectric Coercive Field, Stephen Ducharme, V.M. Fridkin, A.V. Bune, S.P. Palto, L.M. Blinov, N.N. Petukhova, S.G. Yudin

Stephen Ducharme Publications

The Landau-Ginzburg theory of ferroelectricity predicts the intrinsic coercive field for polarization reversal, but the observed extrinsic coercive field is always much smaller as a result of nucleation, dynamic processes not covered by the static theory. We have realized the intrinsic coercive field for the first time, in two-dimensional Langmuir-Blodgett polymer films as thin as 1 nm. The measured coercive field is in good agreement with the theoretical intrinsic value, exhibits the expected dependence on temperature, and does not depend on thickness below 15 nm.


Two-Dimensional Ferroelectrics, L. M. Blinov, V. M. Fridkin, S.P. Palto, A. V. Bune, Peter A. Dowben, Stephen Ducharme Jan 2000

Two-Dimensional Ferroelectrics, L. M. Blinov, V. M. Fridkin, S.P. Palto, A. V. Bune, Peter A. Dowben, Stephen Ducharme

Stephen Ducharme Publications

The investigation of the finite-size effect in ferroelectric crystals and films has been limited by the experimental conditions. The smallest demonstrated ferroelectric crystals had a diameter of ~ 200 A and the thinnest ferroelectric films were ~ 200 A thick, macroscopic sizes on an atomic scale. Langmuir - Blodgett deposition of films one monolayer at a time has produced high quality ferroelectric films as thin as 10 A, made from polyvinylidene fluoride and its copolymers. These ultrathin films permitted the ultimate investigation of finite-size effects on the atomic thickness scale. Langmuir ± Blodgett films also revealed the fundamental two-dimensional character of ferroelectricity in these ...