1 February 1998 Proton spin relaxation study of polar liquid crystals with induced smectic phases
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Detailed frequency dispersion study of proton spin-lattice relaxation times (T1) with Larmor frequency over a wide range using FCNMR technique has been carried out on the binary mixture of 4-Cyanophenyl-4'-octylbenzoate and 4- Cyanobiphenyl-4' (7BCB), exhibiting induced smectic island. The data were analyzed using a composite molecular dynamic model incorporating the different known mechanisms for the spin relaxation. The T1 dispersion in 8CN is essentially dominated by the order director fluctuations (ODF) in the nematic phase, while in 7BCBC they are governed exclusively by the self-diffusion of the molecules. The intermediate nematic phases show a gradual change between the two different scenarios. The formation of smectic phases are accomplished by the near freezing out of the ODF contribution, and sudden slowing down of the diffusion. There orientations show a variation in their correlation times in the nematic phases over these relative concentrations, but show dramatic decrease in correlation times on the formation of layered structures.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
V. Satheesh, V. Satheesh, D. Loganathan, D. Loganathan, K. Venu, K. Venu, V. S. S. Sastry, V. S. S. Sastry, Roman S. Dabrowski, Roman S. Dabrowski, Marzena Brodzik, Marzena Brodzik, "Proton spin relaxation study of polar liquid crystals with induced smectic phases", Proc. SPIE 3318, Liquid Crystals: Physics, Technology, and Applications, (1 February 1998); doi: 10.1117/12.299980; https://doi.org/10.1117/12.299980

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