Electro-optic Kerr effect in the isotropic phase above the columnar phase of a urea derivative.
The authors have measured the electro-optic Kerr effect in the isotropic phase of a urea derivative. Electric-field-induced birefringence Deltan was observed in the isotropic phase even 30 degrees C above the isotropic-columnar phase transition temperature. The induced birefringence is inversely proportional to temperature, as predicted by the Landau-de Gennes theory. Two distinct regions are identified from the proportionality constants in the isotropic phase; optical second-harmonic generation (SHG) is easily observable in the low-temperature region on applying an electric field, whereas SHG activity does not emerge in the higher-temperature region. The structure of molecular assemblies is discussed based on these experimental results.
Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-Okayama, Tokyo, Japan.
Yoshinori
Y
Okada
Fumito
F
Araoka
Yoichi
Y
Takanishi
Ken
K
Ishikawa
Shoichiro
S
Nakahara
Keiki
K
Kishikawa
Hyunhee
H
Choi
Jeong Weon
JW
Wu
Hideo
H
Takezoe
D016880:Anisotropy; D003198:Computer Simulation; D004574:Electromagnetic Fields; D008027:Light; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects*; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition / Q000528:radiation effects; D011829:Radiation Dosage; D014508:Urea / Q000737:chemistry* / Q000528:radiation effects*
D014508:Urea