Evidence of a fractional Debye-Stokes-Einstein law in supercooled o-terphenyl
Evidence of a fractional Debye-Stokes-Einstein law in supercooled o-terphenyl
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DOI：
10.1209/epl/i1997-00301-2
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发表时间：
1997-06-20
期刊：
影响因子：
--
通讯作者：
Leporini, D
中科院分区：
文献类型：
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作者：
Andreozzi, L;DiSchino, A;Leporini, D
用电子自旋共振谱研究了近球形和圆柱形示踪剂在过冷邻三联苯中的转动动力学。在降低温度时，从Debye-Stokes-Einstein定律（DSE）到一个新的DSE（FDSE）D-r与（eta/T）（？）其中xi小于或等于1。D-r是旋转扩散常数，η是剪切粘度，T是温度。圆柱形示踪剂的翻滚和旋转表现出明显的交叉。提出了一种基于动态不均匀性的FDSE简单模型。
The rotational dynamics of nearly spherical and cylindrical tracers dissolved in supercooled o-terphenyl is studied via the Electron Spin Resonance spectroscopy. On decreasing the temperature, a sharp crossover is ob served from the regime where the Debye-Stokes-Einstein law (DSE) holds to a new one which is accounted for by a fractional DSE (FDSE) D-r proportional to (eta/T)(?(-xi)) with xi less than or equal to 1. D-r is the rotational diffusion constant, eta the shear viscosity and T the temperature. Tumbling and spinning of the cylindrical tracer exhibit distinct crossovers. A simple model of FDSE based on the presence of dynamic heterogeneities is presented.