Glass transition inKBr1−xKCNxalloys

It is shown that one can account for the temperature and frequency dependence of the dielectric and quadrupolar relaxations in ${\mathrm{KBr}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{KCN}}_{\mathit{x}}$ with a single interaction energy between nearest neighbors, and a model based on the theory for hierarchically constrained relaxation of Palmer et al. [Phys. Rev. Lett. 53, 958 (1984)]. In particular, the small change in the glass transition temperature with probe frequency can be accounted for. For 0.43≤x≤0.53, the interaction energy deduced from fitting the data is 103 K. A Gaussian distribution of nearest neighbors has been assumed; the width of the distribution, and the orientation of the ion in the unit cell, are left as adjustable parameters.