文章基本信息

标题：On the ergodicity of supercooled molecular glass-forming liquids at the dynamical arrest: the o-terphenyl case
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作者：Francesco Mallamace ; Carmelo Corsaro ; Nancy Leone 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：4
期号：1
DOI：10.1038/srep03747
语种：English
出版社：Springer Nature
摘要：The dynamics of supercooled ortho-terphenyl has been studied using photon-correlation spectroscopy (PCS) in the depolarized scattering geometry. The obtained relaxation curves are analyzed according to the mode-coupling theory (MCT) for supercooled liquids. The main results are: i) the observation of the secondary Johari-Goldstein relaxation ( β ) that has its onset just at the dynamical crossover temperature T_B ( T_M > T_B > T_g ); ii) the confirmation, of the suggestion of a recent statistical mechanical study, that such a molecular system remains ergodic also below the calorimetric glass-transition temperature T_g . Our experimental data give evidence that the time scales of the primary ( α ) and this secondary relaxations are correlated. Finally a comparison with recent PCS experiments in a colloidal system confirms the primary role of the dynamical crossover in the physics of the dynamical arrest.