Electrooptical properties of metal organic ionic liquid crystals

• Autorzy: Klimusheva G. , Koval'chuk A. , Volynets N. , Vakhnin A.
• Języki publikacji: EN

Abstrakty

EN

Electrooptics of smectic liquid crystals has been drawing an increasing interest, especially for new classes of compounds, such as metal alkanoates which manifest as thermotropic as lyotropic smectic mesophases. In the present work, electric and electrooptic properties were studied in detail of pure and dye-doped (polymethine dye) potassium kaproate, a water mixture of which is forming a lyotropic Sm A type liquid crystalline phase at room temperature. As follows from experimental data, for frequencies - f < 3 x 10⁴ Hz, dispersion of the components of complex dielectric permittivity ε' and ε'' is observed. Appropriate relaxation process is described by the Debye equation. On the basis of the analysis of frequency dependencies of ε' ε'' for the frequencies f > 3 x 10⁴ Hz the conductivity of samples on an alternating current was found. The introduction of dye in ionic lyotropic liquid crystals (ILLC) results in increase in conductivity (by 1.5 times) and reduction of relaxation time. The bleaching of the dye in ILLC under the action of a direct voltage (U>5V) was observed. The mechanism explaining "threshold" character of such process was proposed.

Słowa kluczowe

EN

ionic liquid crystals; dielectric permittivity; relaxation process; conductivity; electrooptics

• Wydawca: Stowarzyszenie Elektryków Polskich ; Polska Akademia Nauk ; Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Opto-Electronics Review
• Rocznik: 2002
• Tom: Vol. 10, No. 1
• Strony: 39--42
• Opis fizyczny: Bibliogr. 9 poz.

Twórcy

autor

Klimusheva G.

• Institute of Physics, 46 Nauki Ave., 03-028 Kiev, Ukraine

autor

Koval'chuk A.

• Institute of Physics, 46 Nauki Ave., 03-028 Kiev, Ukraine

autor

Volynets N.

• Institute of Physics, 46 Nauki Ave., 03-028 Kiev, Ukraine

autor

Vakhnin A.

• Institute of Physics, 46 Nauki Ave., 03-028 Kiev, Ukraine

Bibliografia

• 1. T. A. Mirnaya, V. D. Prisyazhnyi, and V. A. Shcherbakov, "The liquid-crystalline state of salt melts containing organic ions", Russ. Chem. Rev. 58, 1429-1450 (1989).
• 2. A. A. Ishchenko, Structure and Spectral Luminescent Properties of Polymethine Dyes, p. 232, Naukova Dumka, Kiev, 1994.
• 3. N. Volynets, N. Derevyanko, A. A. Ishchenko, G. Klimusheva, T. Mirnaya, G. Yaremchuk, and L. Yatsenko, Proc. SPIE 4418, 38-43 (2001).
• 4. F. J. Twarowski and A. C. Albrecht, "Depletion layer studies in organic films: Low frequency capacitance measurements in polycrystalline tetracene", J. Chem. Phys. 20, 2255-2261 (1980).
• 5. A. V. Koval'chuk, "Low-frequency dielectric spectroscopy a an investigation method of electrode - liquid interface", Functional Materials 5, 426-430 (1998).
• 6. T. L. Chelidze A. I. Derevyanko, and O. D. Kurilenko, Electrical Spectroscopy of Heterogeneous Systems, p. 231 Naukova Dumka, Kiev, 1977. (in Russian).
• 7. S. G. Yudin, L. M. Blinov, N. N. Petukhova, and S. P. Palto, "Ferroelectric phase transition in Langmuir-Blodgett films of copper phthalocyanine", JETP Letters 70, 565-648 (1999).
• 8. A. V. Koval'chuk, "Low and infralow - frequency dielectric spectroscopy of the liquid crystal-solid substrate interface. Sliding layers", Ukr. J. Phys. 41, 991-998 (1996). (in Ukrainian).
• 9. A. V. Koval'chuk, "Generation of charge carriers and formation of antisymmetric double electric layers in glycerine", J. Chem. Phys. 108, 8190-8194 (1998).