Fyzikální ústav Akademie věd ČR

Seminář Čtvrtek, 7. květen 2009 - 10:00

Přednášející: Jean-François Legrand (Institut C. Sadron, Université de Strasbourg, France)
Místo: Na Slovance, přednáškový sál v přízemí
Pořadatelé: Oddělení dielektrik
Jazyk přednášky: anglicky

We measured the dynamic structure factor of the liquid and glassy phases of the solution LiCl-6H2O by means of inelastic scattering of radiation in the visible, UV and X-ray range from 1 GHz to 10 THz and by means of photon correlation spectroscopy from 0.01 Hz to 20 kHz. The measurements were performed in a broad temperature range between 353K and 80 K. Our data show that a single relaxation process, which at high temperature has features similar to those of the single relaxation of pure water, starts to differentiate into two relaxations : structural (alpha-) and secondary (beta-), upon cooling below 220 K. On cooling the system at lower temperature, the relaxation strength reveal an uncommon behavior with respect to most glass-forming systems : the beta-relaxation is the continuation of the single process existing at high temperature and an onset occurs for the alpha-relaxation from the beta-process.