Stability of Molecular Order in the Smectic a Phase of a Liquid Crystal
Ethyl-[p-(p-methoxybenzilidene)-amino]-cinnamate (EMC) was ordered in its smectic A phase by ordering in the nematic phase and cooling through the nematic-smectic A phase transition in the presence of a magnetic field. The direction and degree of order were determined using pulsed nuclear magnetic resonance techniques. The order was observed to change with time following a rotation of the magnetic field. The degree and stability of order produced were found to be functions of the concentration of small amounts of decomposition products. A model is discussed that satisfactorily accounts for the time dependence of the reordering.
KeywordsMagnetic Field Decomposition Product Free Induction Decay Nematic Phase Molecular Order
Unable to display preview. Download preview PDF.
Footnotes and References
- 1.C.E. Tarr and A.M. Fuller, Fourth International Liquid Crystal Conference, Kent State University, August 1972 (to appear J. Mol. Cryst. and Liquid Cryst.)Google Scholar
- 2.Eastman Kodak Co., Eastman Organic Chemicals, Rochester, N.Y.Google Scholar
- 4.G.H. Brown, J.W. Doane, and V.D. Neff, Critical Reviews in Solid State Sciences 1, 344 ff. (1970).Google Scholar
- 7.A.M. Fuller, Ph.D. Thesis, University of Maine, 1973 (unpublished).Google Scholar