Spin-Lattice Relaxation in Nematic Liquid Crystals Via the Modulation of the Intramolecular Dipolar Interactions by Order Fluctuations

1976 ◽  
pp. 97-111 ◽  
Author(s):  
R. Blinc
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Dipolar Interactions ◽  
Spin Lattice

Theory for spin-lattice relaxation in nematic liquid crystals

1976 ◽  
Vol 14 (1) ◽  
pp. 414-423 ◽  
Author(s):  
P. Ukleja ◽  
J. Pirs ◽  
J. W. Doane
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

Mechanisms for spin-lattice relaxation in nematic liquid crystals

1972 ◽  
Vol 11 (8) ◽  
pp. 1073-1075 ◽  
Author(s):  
M. Vilfan ◽  
R. Blinc ◽  
J.W. Doane
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

Proton Spin Lattice Relaxation in the Dimethylammonium Group

1993 ◽  
Vol 48 (5-6) ◽  
pp. 713-719
Author(s):  
K. Venu ◽  
V. S. S. Sastry
Keyword(s):  
Experimental Data ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Methyl Groups ◽  
Dipolar Interactions ◽  
Spin Temperature ◽  
Spin Lattice ◽  
Molecular Group

Abstract A model for the spin lattice relaxation time of the protons of dimethylammonium in the Redfield limit and common spin temperature approximation is developed. The three fold reorientations of the methyl groups, the rotation of the whole molecular group around its two fold symmetric axis and possible correlations among these motions are considered. The effect of these processes on the dipolar interactions among the protons within the same molecular group is taken into account. The resulting relaxation rate is powder averaged and used to explain the experimental data in literature on [NH2(CH3)2]3Sb2Br9 . The analysis shows that dynamically inequivalent groups exist in this compound and that the effect of proposed correlation among the different motions on the final results is negligible.

Intermolecular and intramolecular contributions to the proton spin-lattice relaxation of the liquid crystal 4-cyano-4′-n-pentyl-d11-biphenyl: nematic and supercooled nematic regions

1987 ◽  
Vol 65 (2) ◽  
pp. 115-121 ◽  
Author(s):  
John S. Lewis ◽  
E. Tomchuk ◽  
E. Bock
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Qualitative Agreement ◽  
Nonlinear Least Squares ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Experimental Results ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Fitting Parameters

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.

Nuclear spin-lattice relaxation rates in liquid crystals

1986 ◽  
Vol 59 (1) ◽  
pp. 97-125 ◽  
Author(s):  
P.A. Beckmann ◽  
J.W. Emsley ◽  
G.R. Luckhurst ◽  
D.L. Turner
Keyword(s):  
Liquid Crystals ◽  
Nuclear Spin ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Nuclear Spin Lattice Relaxation
Sign in / Sign up

Export Citation Format

Share Document