Nonlinear susceptibility measurements in a supercooled liquid close to Tg: Growth of the correlation length and possible critical behavior

C. Crauste-Thibierge (1, 2) , C. Brun (3, 4) , F. Ladieu (3, 2) , D. L'Hôte (3, 2) , G. Biroli (5) , J.-P. Bouchaud (3, 2)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 SPEC - UMR3680 - Service de physique de l'état condensé
3 SPHYNX - Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes
4 INSP - Institut des Nanosciences de Paris
5 IPHT - Institut de Physique Théorique - UMR CNRS 3681

The existence of a growing correlation length associated with the strong increase of relaxation times of glass-formers close to the glass transition is still a major open question in glass physics. It has been recently proposed that the ac nonlinear susceptibility of a supercooled liquid close to the glass transition temperature T g would be a probe of dynamical correlations. As for spin glasses, where the nonlinear susceptibility diverges at the transition, this quantity is tailored to reveal the possible “hidden” critical behavior of the glass transition. We have developed a high sensitivity experimental device to measure the nonlinear dielectric susceptibility of an insulating material at finite frequency. It measures the third harmonics of the current flowing out of a capacitor with the supercooled liquid as the dielectric layer. It is based on a bridge with two capacitors, and reaches a sensitivity better than 10 −7 (ratio of third to first harmonics). Our first results on supercooled glycerol are presented. They clearly reveal the growing of the correlations close to the glass transition

Domains: Physics [physics]

C. Crauste-Thibierge, C. Brun, F. Ladieu, D. L'Hôte, G. Biroli, et al.. Nonlinear susceptibility measurements in a supercooled liquid close to Tg: Growth of the correlation length and possible critical behavior. Journal of Non-Crystalline Solids, 2011, 357 (2), pp.279 - 281. ⟨10.1016/j.jnoncrysol.2010.05.090⟩. ⟨cea-01394765⟩