Nonlinear dielectric response of poled amorphous polymer dipole glasses

• Published in: Journal of non-crystalline solids 2005-09, Vol.351 (33), p.2759-2763
• Main Authors: Bauer, Siegfried, Bauer-Gogonea, Simona, Ploss, Beatrix, Ploss, Bernd
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric loss and relaxation; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Permittivity (dielectric function); Physics; Piezoelectricity and electromechanical effects
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2005.03.068

Temperature-dependent spectra of the linear, second- and third-order nonlinear dielectric permittivities are reported for an amorphous polymethylmethacrylate/Disperse Red 1 guest–host polymer and a poly(styrene maleic anhydride)-Disperse Red 1 side-chain polymer glass. Both polymer systems contain Disperse Red 1 chromophores, a very strong molecular dipole. In guest–host polymers with low dye loading, the dipole density and dipole moment of the chromophores can be determined from the linear and third-order nonlinear dielectric relaxation strength, associated with the micro-Brownian motion of the chromophore dipoles. The second-order nonlinear dielectric permittivity is non-vanishing in the glassy state only in poled polymers. Contributions to the second-order dielectric permittivity arise from piezoelectricity and from the elasto-optical and electronic electro-optical Pockels effect. In poled polymer dipole glasses with nonlinear optically active chromophores, the electronic electro-optical response is the dominant source for the second-order nonlinear dielectric permittivity. Therefore, electrical current versus voltage measurements enable a measurement of the electro-optical Pockels effect in poled polymer chromophore dipole glasses.