Dislocation polarization and space-charge relaxation in solid solutions ${\mathrm{Ba}}_{1\mathrm{-}\mathrm{x}}$${\mathrm{La}}_{\mathrm{x}}$${\mathrm{F}}_{2+\mathrm{x}}$

Concentrated solid solutions ${\mathrm{Ba}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{La}}_{\mathrm{x}}$ ${\mathrm{F}}_{2+\mathrm{x}}$, x≤0.492, are studied by means of thermally stimulated depolarization [ionic thermal current (ITC)] or polarization [thermally stimulated polarization current (TSPC)] techniques. At high temperature two peaks are reported whose maxima shift to lower temperatures as x increases. The energies calculated for these relaxation processes are compared to the enthalpies deduced from conductivity measurements. The first high-temperature peak, D, has been already reported in a more restricted concentration range and has been attributed to either a space-charge accumulation near the electrodes or the polarization of the dislocations present in the crystal.