Nitrogen Nuclear Quadrupole Resonance Dips in the Proton Spin Relaxation Dispersion of Nematic and Smectic Thermotropic Liquid Crystals
نویسنده
چکیده
für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namensnennung 4.0 Lizenz. Nitrogen Nuclear Quadrupole Resonance Dips in the Proton Spin Relaxation Dispersion of Nematic and Smectic Thermotropic Liquid Crystals
منابع مشابه
Frequency Dispersion of the Proton Zeeman Spin-lattice Relaxation in the Smectic Phases of Tbba
Using a field cycling technique, the Larmor frequency (VL) dependence of the proton Zeeman spin-lattice relaxation time T I has been measured in the smectic A, smectic C, smectic B and smectic VII phases of terephtal-bis-butylaniline (TBBA) between VL = 90 MHz and V L = 0.14 MHz and a significant dispersion has been found. The observed c o i J 2 dispersion law in the smectic A phase and the dev...
متن کاملN NQR and Orientational Ordering in Smectic Liquid Crystals
Liquid crystals are systems which flow like liquids while retaining the mechanical and optical anisotropy of crystals. On a microscopic level they are characterized by molecular orientational order accompanied by a partial or complete translational disorder of the molecular positions (1~3) • Thermotropic liquid crystals are formed upon heating many anisotropic organic compounds, while lyotropic...
متن کاملEnergy landscape view of phase transitions and slow dynamics in thermotropic liquid crystals.
Thermotropic liquid crystals are known to display rich phase behavior on temperature variation. Although the nematic phase is orientationally ordered but translationally disordered, a smectic phase is characterized by the appearance of a partial translational order in addition to a further increase in orientational order. In an attempt to understand the interplay between orientational and trans...
متن کاملElectron Spin Resonance Studies of Anisotropic Ordering, Spin Relaxation, and Slow Tumbling in Liquid Crystalline Solvents. 3. Smecticd
In this work the nonaxial ordering and spin relaxation of PD-Tempone spin probe in several liquid crystalline solvents exhibiting smectic A and B phases were studied utilizing methods previously employed by Polnaszek and Freed for the study of nematic liquid crystals. The results rleported here for the isotropic and nematic phases are generally in accord with those obtained previously. An analy...
متن کامل