TY - JOUR
T1 - Dielectric response in the Smectic A and Smectic C* phases of a ferroelectric liquid crystal, 12CN5(R*)
AU - George, A. K.
AU - Al-Hinai, Mariam
AU - Carboni, C.
AU - Al-Harthi, S. H.
AU - Potukuchi, D. M.
AU - Naciri, J.
N1 - Funding Information:
Keywords: arrhenius plots; cole–cole plots; dielectric relaxation frequency; ferroelectric liquid crystals; goldstone and soft mode This work was supported by project No.IG/SCI/PHYS/00/02 financed by Sultan Qaboos University. One of the authors, DMP, gratefully acknowledges Sultan Qaboos University for the Visiting Consultant position offered to him. *Corresponding author. E-mail: akgeorge@squ.edu.om
PY - 2004
Y1 - 2004
N2 - This paper reports the results of the dielectric relaxation studies performed in the Smectic A (SmA) and Smectic C* (SmC*) phases of the ferroelectric liquid crystal, 12CN5(R*) in the frequency range 5Hz to 13MHz. Planar orientation used throughout the study was achieved by rubbed polyamide coating on the surfaces of the dielectric cell. Transition temperatures determined from the derivative of this dielectric permittivity agrees with that obtained using thermal polarizing microscopy. The dielectric spectrum in the SmA phase shows single relaxation, whereas the SmC* phase has two relaxations, viz., the low frequency Goldstone mode and the high frequency soft mode. Special attention was paid to the study of the low frequency Goldstone mode relaxation. From the Cole-Cole plots, the temperature dependence of dielectric strength (Δε), the relaxation frequency (fR) and the distribution parameter (x) ralevant to the Goldstone mode have been estimated. The relaxation frequency follows the Arrhanius relation in the asymptotic regions far from the transition. Results of the bias-dependent dielectric, measurements of the Goldstone made relaxation, have also been presented.
AB - This paper reports the results of the dielectric relaxation studies performed in the Smectic A (SmA) and Smectic C* (SmC*) phases of the ferroelectric liquid crystal, 12CN5(R*) in the frequency range 5Hz to 13MHz. Planar orientation used throughout the study was achieved by rubbed polyamide coating on the surfaces of the dielectric cell. Transition temperatures determined from the derivative of this dielectric permittivity agrees with that obtained using thermal polarizing microscopy. The dielectric spectrum in the SmA phase shows single relaxation, whereas the SmC* phase has two relaxations, viz., the low frequency Goldstone mode and the high frequency soft mode. Special attention was paid to the study of the low frequency Goldstone mode relaxation. From the Cole-Cole plots, the temperature dependence of dielectric strength (Δε), the relaxation frequency (fR) and the distribution parameter (x) ralevant to the Goldstone mode have been estimated. The relaxation frequency follows the Arrhanius relation in the asymptotic regions far from the transition. Results of the bias-dependent dielectric, measurements of the Goldstone made relaxation, have also been presented.
KW - Arrhenius plots
KW - Cole-cola plots
KW - Dielectric relaxation frequency
KW - Ferroelectric liquid crystals
KW - Goldstone and soft mode
UR - http://www.scopus.com/inward/record.url?scp=9544225912&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=9544225912&partnerID=8YFLogxK
U2 - 10.1080/15421400490431714
DO - 10.1080/15421400490431714
M3 - Conference article
AN - SCOPUS:9544225912
SN - 1542-1406
VL - 409
SP - 343
EP - 353
JO - Molecular Crystals and Liquid Crystals
JF - Molecular Crystals and Liquid Crystals
T2 - Proceedings of the 19th International Liquid Crystal Conference, ILCC2002
Y2 - 30 June 2002 through 5 July 2002
ER -