INVESTIGADORES
BONETTO fernando Jose
artículos
Título:
Apparent low-field spin-lattice dispersion in the smectic A mesophase of thermotropic cyanobiphenyls
Autor/es:
E. ANOARDO; F. BONETTO; R. KIMMICH
Revista:
PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS
Editorial:
American Physical Society (APS)
Referencias:
Lugar: Ridge, New York, USA; Año: 2003 vol. 68 p. 227011 - 227014
ISSN:
1063-651X
Resumen:
Proton field-cycling spin-lattice relaxometry (T_1) of the smectic A mesophase in cyanobiphenyls revealed the presence of steep dispersions in the low frequency regime. We clearly show for the first time that the strong dispersion characteristic of smectic organizations cannot be attributed to the collective molecular dynamics (order director fluctuations), as it is usually interpreted. We present two independent experimental evidences: the dependence of the dispersion with the slew-rate of the magnetic field cycle, and the dependence of the dispersion with the presence and power of an ultrasonic field.