Activation Processes in Superionic Rare Earth Trifluorides

the specific features of activation processes in superionic crystals with diffuse phase transitions were studied for crystals of light rare earth trifluorides LnF3 such as lanthanum trifluoride LaF3 and its analogs CeF3, PrF3. The energy parameters of the thermal disordering of the lattice of superionics were obtained by the methods of Raman scattering. It is shown that in the investigated temperature range, the broadening of vibrational lines is mainly associated with the damping of vibrations, due to the movement of fluorine ions into lattice interstices with high mobility. It is also shown that for each case of recording the vibrational spectrum of the superionic crystals, there is a threshold value of the concentration of disordered ions, starting from which it is possible to detect the effect of temperature and structural disorder on the properties of the medium and the parameters of spectral lines.