Static Freezing Transition at a Finite Temperature in a Quasi-One-Dimensional Deuteron Glass

The dipolar freezing process of a quasi-one-dimensional betaine deuteron glass was studied using linear and nonlinear dielectric spectroscopy. The linear response as measured for frequencies $5\mathrm{mHz}<\nu <200\mathrm{}\mathrm{MHz}$ was analyzed using the recently invented $\delta$ plot, providing evidence for a static freezing transition near 30 K. Measurements of the ergodic to nonergodic transition as well as of the incipient divergence of the nonlinear susceptibility yield independent confirmation of this quasistatic freezing transition temperature. The critical exponent describing the nonlinear behavior is found to be $\gamma =1\mathrm{}$, compatible with mean-field predictions.