Dielectric response of doped Bi$_{12}$TiO$_{20}$: Ru crystals in an alternating electric field

The results of examination of AC dependences of capacitance and dielectric loss tangent of sillenite Bi$_{12}$TiO$_{20}$ crystals doped with ruthenium on frequency are presented. Non-Debye dispersion of dielectric coefficients is found in the frequency interval of 5 $\times$ 10$^{2}$–10$^{5}$ Hz, and a resonance phenomenon is observed. Polarization processes in the studied samples are attributed to relaxators associated with metal–oxygen vacancies and structural elements incorporating 6$s^2$ lone-pair electrons.