TY  - JOUR
A1  - Pham, Cong Duc
A1  - Petre, Anca
A1  - Berquez, Laurent
A1  - Flores Suárez, Rosaura
A1  - Mellinger, Axel
A1  - Wirges, Werner
A1  - Gerhard, Reimund
T1  - 3D high-resolution mapping of polarization profiles in thin poly(vinylidenefluoride-trifluoroethylene) (PVDF- TrFE) films using two thermal techniques
N2  - In this paper, two non-destructive thermal methods are used in order to determine, with a high degree of accuracy, three-dimensional polarization distributions in thin films (12 mu m) of poly(vinylidenefluoride- trifluoroethylene) (PVDF-TrFE). The techniques are the frequency-domain Focused Laser Intensity Modulation Method (FLIMM) and time-domain Thermal-Pulse Tomography (TPT). Samples were first metalized with grid-shaped electrode and poled. 3D polarization mapping yielded profiles which reproduce the electrode-grid shape. The polarization is not uniform across the sample thickness. Significant polarization values are found only at depths beyond 0.5 mu m from the sample surface. Both methods provide similar results, TPT method being faster, whereas the FLIMM technique has a better lateral resolution.
Y1  - 2009
UR  - http://ieeexplore.ieee.org/servlet/opac?punumber=94
U6  - https://doi.org/10.1109/TDEI.2009.5128505
SN  - 1070-9878
ER  - 
TY  - JOUR
A1  - Ganesan, Lakshmi Meena
A1  - Frübing, Peter
A1  - Mellinger, Axel
A1  - Gerhard, Reimund
T1  - Dielectric relaxation behaviour of nematic liquid crystals dispersed in poly(vinylidene fluoride- trifluoroethylene)
N2  - Polymer-dispersed liquid crystals (PDLCs) are prepared from poly(vinylidene fluoride-trifluoroethylene) (P(VDF- TrFE)) and a nematic liquid-crystal (LC). The anchoring effect was studied using dielectric relaxation spectroscopy. Two dispersion regions are observed in the dielectric spectra of the pure P(VDF-TrFE) film. They are related to the glass transition and to a space-charge relaxation. In PDLC films containing 10 wt% of LC, an additional, bias field-dependent relaxation peak is found that can be attributed to the motion of LC molecules. Due to the hindered movement of the LC molecules, this relaxation process is considerably slowed down, compared with the related process in the pure LC.
Y1  - 2009
UR  - http://iopscience.iop.org/0022-3727/
U6  - https://doi.org/10.1088/0022-3727/42/9/092006
SN  - 0022-3727
ER  -