Dielectric beta relaxations in the glassy state of salol?

Citation
H. Wagner et R. Richert, Dielectric beta relaxations in the glassy state of salol?, J CHEM PHYS, 110(23), 1999, pp. 11660-11663
Citations number
21
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CHEMICAL PHYSICS
ISSN journal
00219606 → ACNP
Volume
110
Issue
23
Year of publication
1999
Pages
11660 - 11663
Database
ISI
SICI code
0021-9606(19990615)110:23<11660:DBRITG>2.0.ZU;2-9
Abstract
The recently observed possibility to suppress the beta-relaxation intensity of omicron-terphenyl by annealing at temperatures below the glass transiti on guided us to ask, whether the absence of a dielectric beta process in ma ny glass-forming materials, e.g., salol (phenyl salicylate), is a matter of the slow cooling rates usually employed to enter the glassy state. In orde r to assess this issue, we have quenched liquid salol to well below T-g at a rate of dT/dt = -490 K/min. Opposed to the case of cooling rates around - 5 K/min or slower, this highly quenched sample displays a symmetric dielect ric relaxation peak near f = 10(3) Hz with an appreciable relaxation streng th, Delta epsilon = 6 X 10(-3). This novel feature of salol disappears irre versibly after a temperature excursion towards the glass transition at T-g = 220 K. (C) 1999 American Institute of Physics. [S0021-9606(99)50823-4].