%0 Journal Article
%T Peculiarities in the Director Reorientation and the NMR Spectra Evolution in a Nematic Liquid Crystals under the Effect of Crossed Electric and Magnetic Fields
%J Crystals | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/cryst9050262
%X The illustrative description of the field-induced peculiarities of the director reorientation in the microsized nematic volumes under the effect of crossed magnetic B and electric E fields have been proposed. The most interesting feature of such configuration is that the nematic phase becomes unstable after applying the strong E . The theoretical analysis of the reorientational dynamics of the director field provides an evidence for the appearance of the spatially periodic patterns in response to applied large E directed at an angle ¦Á to B . The feature of this approach is that the periodic distortions arise spontaneously from a homogeneously aligned nematic sample that ultimately induces a faster response than in the uniform mode. The nonuniform rotational modes involve additional internal elastic distortions of the conservative nematic system and, as a result, these deformations decrease of the viscous contribution U vis to the total energy U of the nematic phase. In turn, that decreasing of U vis leads to decrease of the effective rotational viscosity coefficient ¦Ã eff ( ¦Á ) . That is, a lower value of ¦Ã eff ( ¦Á ) , which is less than one in the bulk nematic phase, gives the less relaxation time ¦Ó on ( ¦Á ) ¡« ¦Ã eff ( ¦Á ) , when ¦Á is bigger than the threshold value ¦Á th . The results obtained by Deuterium NMR spectroscopy confirm theoretically obtained dependencies of ¦Ó on ( ¦Á ) on ¦Á . View Full-Tex
%U https://www.mdpi.com/2073-4352/9/5/262