Propylene Carbonate Reexamined: Mode-Coupling ${\hat{I}}^2$ Scaling without Factorisation ?

Abstract

The dynamic susceptibility of propylene carbonate in the moderately viscous regime above $T_{\mathrm{c}}$ is reinvestigated by incoherent neutron and depolarised light scattering, and compared to dielectric loss and solvation response. Depending on the strength of $\hat{I}\pm$ relaxation, a more or less extended ${\hat{I}}^2$ scaling regime is found. Mode-coupling fits yield consistently $\hat{I}»=0.72$ and $T_{\mathrm{c}}=182$K, although different positions of the susceptibility minimum indicate that not all observables have reached the universal asymptotics.