Temperature dependence of characteristic length for glass transition.

The temperature dependence of the characteristic length for the dynamic glass transition in ortho-terphenyl is determined, for the first time, from combined results of depolarized dynamic light scattering, photon correlation spectroscopy, and viscosity experiments. The length is found to vary according to ${\ensuremath{\xi}}_{\mathit{a}}$\ensuremath{\sim}(T-${\mathit{T}}_{\mathrm{\ensuremath{\infty}}}$${)}^{\mathrm{\ensuremath{-}}\ensuremath{\nu}}$ where ${\mathit{T}}_{\mathrm{\ensuremath{\infty}}}$ is the Vogel temperature, with an exponent \ensuremath{\nu}-0.69\ifmmode\pm\else\textpm\fi{}0.06 in the temperatur region from up ${\mathit{T}}_{\mathit{g}}$ up to ${\mathit{T}}_{\mathit{g}}$+80 K.