Relaxation properties of proton magnetic spin quasi-invariants in liquid crystals

Autor:	C. E. González, O. Mensio, Ronald Y. Dong, R. C. Zamar, Daniel J. Pusiol
Rok vydání:	2002
Předmět:	Thermal equilibrium Materials science Proton Condensed Matter Physics Molecular physics Thermotropic crystal Electronic Optical and Magnetic Materials Spin magnetic moment Molecular dynamics Dipole Nuclear magnetic resonance Liquid crystal Molecule Electrical and Electronic Engineering
Zdroj:	Physica B: Condensed Matter. 320:416-418
ISSN:	0921-4526
Popis:	We present an experimental study of the thermodynamic properties of proton pairs in two thermotropic nematic liquid crystals: chain deuterated 4-n-pentyl-4′-cyanobyphenyl, 5CBd11, and normal 5CB. In the first sample, we find the existence of pure intra-pair and inter-pair magnetic quasi-invariants. In the second, the dipolar signal is more complex, due to the nonequivalence of protons pairs in the molecule, but it is still possible to prepare states for which only one kind of order strongly dominates. In both compounds, the dipolar quasi-invariants relax independently to thermal equilibrium with the lattice. Finally, we discuss the temperature dependence of the characteristic relaxation times in terms of local and long-range cooperative molecular dynamics.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6c3f95826117516f9abe9220fec466cf https://doi.org/10.1016/s0921-4526(02)00763-9 Zobrazit plný text záznamu Full Text from ScienceDirect