Dispersion of proton spin-lattice relaxation in a cholesteric liquid crystal

1983 ◽  
Vol 44 (10) ◽  
pp. 1179-1184 ◽  
Author(s):  
M. Vilfan ◽  
R. Blinc ◽  
J. Dolinšek ◽  
M. Ipavec ◽  
G. Lahajnar ◽  
...  
1987 ◽  
Vol 65 (2) ◽  
pp. 115-121 ◽  
Author(s):  
John S. Lewis ◽  
E. Tomchuk ◽  
E. Bock

The intermolecular and intramolecular contributions to proton spin-lattice relaxation in 4-cyano-4′-n-pentyl-d11-biphenyl (5CB-d11) have been measured as a function of temperature and frequency. The theories of relaxation in nematic liquid crystals are presented in a form suitable for nonlinear least squares fitting to the data, and the experimental results compared with appropriate theories. It is found experimentally that it is not possible to distinguish between the Freed and the Ukleja et al. theories on intramolecular spin-lattice relaxation or between the Zumer–Vilfan and the Ukleja et al. theories on intermolecular spin-lattice relaxation. All three theories are in more or less equal qualitative agreement with experimental results and yield fitting parameters of comparable physical plausibility.


1976 ◽  
Vol 54 (22) ◽  
pp. 2282-2286 ◽  
Author(s):  
J. J. Visintainer ◽  
E. Bock ◽  
Ronald Y. Dong ◽  
E. Tomchuk

Proton line shapes and spin–lattice relaxation were studied in the isotropic phase of the liquid crystal n-p-cyanobenzylidene-p-n-octyloxyaniline (CBOOA) using Fast Fourier Transform (FFT) spectroscopy. The proton spin–lattice relaxation time T1 above the nematic–isotropic phase transition was measured, at several Larmor frequencies, for the resolved peaks in the FFT spectra. The critical temperature dependences of (T1)cf, the T1, due to collective order fluctuations, are thus studied for the aromatic and the alkyl proton groups. The critical temperature behavior of CBOOA is compared with the predictions of the model based on short-range nematic orientational order fluctuations.


1993 ◽  
Vol 14 (2) ◽  
pp. 415-426 ◽  
Author(s):  
A. Ferraz ◽  
J. L. Figueirinhas ◽  
P. J. Sebastião ◽  
A. C. Ribeiro ◽  
H. T. Nguyen ◽  
...  

1968 ◽  
Vol 6 (12) ◽  
pp. 839-841 ◽  
Author(s):  
R. Blinc ◽  
D.E. O'Reilly ◽  
E.M. Peterson ◽  
G. Lahajnar ◽  
I. Levstek

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