Evidence of a fractional Debye-Stokes-Einstein law in supercooled o-terphenyl

被引：88

作者：

Andreozzi, L ^{[1
]}

DiSchino, A ^{[1
]}

Giordano, M ^{[1
]}

Leporini, D ^{[1
]}

机构：

[1] UNIV PISA,DIPARTIMENTO FIS,I-56126 PISA,ITALY

来源：

EUROPHYSICS LETTERS | 1997年 / 38卷 / 09期

关键词：

D O I：

10.1209/epl/i1997-00301-2

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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.

引用

页码：669 / 674

页数：6

共 30 条

[1] Jump reorientation of a molecular probe in the glass transition region of o-terphenyl [J].