On the ergodicity of supercooled molecular glass-forming liquids at the dynamical arrest: the o-terphenyl case
Author(s)Mallamace, Francesco; Corsaro, Carmelo; Leone, Nancy; Villari, Valentina; Micali, Norberto; Chen, Sow-Hsin; ... Show more Show less
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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[subscript B] (T[subscript M] > T[subscript B] > T[subscript 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[subscript 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.
DepartmentMassachusetts Institute of Technology. Department of Nuclear Science and Engineering
Nature Publishing Group
Mallamace, Francesco, Carmelo Corsaro, Nancy Leone, Valentina Villari, Norberto Micali, and Sow-Hsin Chen. “On the Ergodicity of Supercooled Molecular Glass-Forming Liquids at the Dynamical Arrest: The o-Terphenyl Case.” Sci. Rep. 4 (January 17, 2014).
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