Direct Observation of Diffuse Cone Behavior in De Vries Smectic-A and -C Phases of Organosiloxane MesogensPhysical Review Letters
- Resolution X Ray,
- Liquid Crystals,
- Layer Thickness,
AbstractSimultaneous and direct x-ray measurements of the smectic layer spacing, molecular tilt, and orientational order in the de Vries smectic A (SmA) and C (SmC) phases of two organosiloxane mesogens reveal that (i) the SmC (tilt) order parameter exponent beta = 0.26 +/- 0.01 for 2nd order SmA-SmC transition-in excellent agreement with the tricritical behavior, (ii) the siloxane and hydrocarbon parts of the molecules are segregated and oriented parallel to the director with very different degree of orientational order, and (iii) thermal evolution of the effective molecular length is different in the two phases.
Citation InformationHyungGuen Yoon, Dena M. Agra-Kooijman, Khurshid Ayub, Robert P. Lemieux, et al.. "Direct Observation of Diffuse Cone Behavior in De Vries Smectic-A and -C Phases of Organosiloxane Mesogens" Physical Review Letters Vol. 106 Iss. 8 (2011)
Available at: http://works.bepress.com/satyendra_kumar/39/