New approach to treating the energetics of activation processes in the lattice of superionic conductors with intrinsic structural disorder

Using LaF$_3$-type superionic trifluorides as an example, it is shown that the intrinsic thermal structural disorder not affecting the symmetry of the lattice is embodied in light inelastic scattering spectra. Tools for analyzing the Arrhenius-like temperature dependence of the activation energy of disordering in the superionic conductor lattice are discussed. It is found that activation energy $\Delta E_a$ found from the temperature dependence of the Raman line width is many times lower than energy $E_a$ responsible for LaF$_3$ lattice disordering.