In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 38, No. 9A ( 1999-09-01), p. L1042-
Abstract:
A pyroelectric technique was used for direct measurements of the flexoelectric polarization P f in hybrid aligned nematic cells filled with a guest host mixture (4-pentyl-4 ′ -cyanobiphenyl (5CB) doped with an azo-dye). Under UV-light excitation, the mixture manifested strong photochromism due to an almost complete conversion of the rod-shaped trans -isomers of the azobenzene moiety into long-living banana-shaped cis -isomers. The temperature dependences of P f and, consequently, the sum of the flexoelectric coefficients ( e 1 + e 3 ) were measured in situ without and with UV illumination and the kinetics of P f was shown to follow the kinetics of trans - cis - trans isomerization. UV light induced decrease in ( e 1 + e 3 ), that is, a negative “photo-flexoelectric effect” is accounted for by a decrease in the orientational order parameter of the mixture caused by the strongly bent cis -isomers.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.38.L1042
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1999
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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