Determination of Orientational Order Parameters of Two Tri-Component Mixtures from Optical Birefringence and X-Ray Diffraction Measurements |
| S. Basak a, P. Dasgupta a, B. Dasa, M.K. Das b and R. Dabrowski c
aDepartment of Physics, Siliguri Institute of Technology, Siliguri, Darjeeling - 734 009, India bDepartment of Physics, University of North Bengal, Siliguri, Darjeeling - 734 013, India cDepartment of Advanced Technologies and Chemistry, Military University of Technology, 00-908 Warsaw, Poland |
| Received: May 16, 2011; In final form: August 2, 2011 |
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| Two tri-component mixtures as base mixtures for vertically aligned mode LCD's were prepared. The eutectic compositions were theoretically estimated and experimentally verified from differential scanning calorimetry studies. A room temperature nematic mixture with fairly broad operating range emerged from each of the tri-component mixtures. The optical birefringence of these mixtures at the eutectic composition was measured as a function of temperature. X-ray diffraction measurements were done on these mixtures to obtain the orientational order parameters as a function of temperature. The order parameter values were also determined from birefringence measurements and the results were compared with mean field theory. Structural parameters like intermolecular distance and apparent molecular length have also been determined. |
| DOI: 10.12693/APhysPolA.120.1037 PACS numbers: 61.05.cp, 61.30.-v, 42.70.Df |