IN-SITU X-RAY MEASUREMENTS OF LIGHT-CONTROLLED LAYER SPACING IN A SMECTIC-A LIQUID CRYSTAL TATIANA A. KRENTSEL (LOBKO), OLEG D. LAVRENTOVICH, and SATYENDRA KUMAR
نویسندگان
چکیده
The smectic-A phase of octylcyanobiphenyl (8CB) doped with a photosensitive azo-compound has been reported to exhibit structural changes and formation of periodic layers distortions upon exposure to low-level radiation. It is caused by changes in the smectic layer spacing triggered by light-induced molecular photoisomerization of the dopant azocompound. Our in-situ highresolution x-ray scattering study reveals that the light irradiation controls the smectic spacing. The exposure to UV light increases the layer spacing by as much as 0.5% ( 0.155A for the studied mixture of 8CB and diheptylazobenzene 7AB at T = 24.00°C). Irradiation by He-Ne lasm at 633 nm causes the contraction of the layers.
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