Interdependence of Primary and Johari-Goldstein Secondary Relaxations in Glass-Forming Systems
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- 作者：K. Kessairi ; S. Capaccioli ; D. Prevosto ; M. Lucchesi ; S. Sharifi ; P. A. Rolla
- 刊名：Journal of Physical Chemistry B
- 出版年：2008
- 出版时间：April 17, 2008
- 年：2008
- 卷：112
- 期：15
- 页码：4470 - 4473
- 全文大小：162K
- 年卷期：v.112,no.15(April 17, 2008)
- ISSN：1520-5207
文摘
We report evidence from broadband dielectric spectroscopy that the dynamics of the primary 
- and secondaryJohari-Goldstein (JG) 
ddle">-processes are strongly correlated in different glass-forming systems over a widetemperature T and pressure P range, in contrast with the widespread opinion of statistical independence ofthese processes. The -ddle"> mutual dependence is quantitatively confirmed by (a) the overall superposition ofspectra measured at different T-P combinations but with an invariant -relaxation time; (b) the contemporaryscaling of the isothermal-pressure and isobaric-temperature dependences of the -and ddle">-relaxation times asplotted versus the reduced variable Tg(P)/T where Tg is the glass transition temperature. These novel andmodel-independent evidences indicate the relevance of the JG relaxation phenomenon in glass transition,often overlooked by most current theories.
- and secondaryJohari-Goldstein (JG) ddle">-processes are strongly correlated in different glass-forming systems over a widetemperature T and pressure P range, in contrast with the widespread opinion of statistical independence ofthese processes. The -ddle"> mutual dependence is quantitatively confirmed by (a) the overall superposition ofspectra measured at different T-P combinations but with an invariant -relaxation time; (b) the contemporaryscaling of the isothermal-pressure and isobaric-temperature dependences of the -and ddle">-relaxation times asplotted versus the reduced variable Tg(P)/T where Tg is the glass transition temperature. These novel andmodel-independent evidences indicate the relevance of the JG relaxation phenomenon in glass transition,often overlooked by most current theories.