Scanning pyroelectric microscopy revealing the spatial polarity distribution in topologically centric crystals of trans-4-chloro-4'-nitrostilbene.
Scanning pyroelectric microscopy (SPEM) was applied to investigate grown-in polarity in trans-4-chloro-4'-nitrostilbene (CNS) single crystals. Sectors {011} and {011} were scanned for cross sections perpendicular to the a-direction. A rotational analysis for {011}, {011} faces was performed for a needle like crystal turned around the a-axis. All pyroelectric experiments confirm a bipolar grown-in state of polarity for sector involving the twofold axis b. These measurements agree with theoretical force field and stochastic calculations, predicting a bipolar state and a nearly identical extent of polarity for two different sectors.
Behrnd
N-R
NR
Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, CH-3012, Berne, Switzerland.
Couderc
G
G
Wübbenhorst
M
M
Hulliger
J
J