Аннотация:Single crystals of (Pb0.86Sr0.14)5Ge3O11 are prepared by a slow melt cooling. The effect of high-energy electron irradiation with fluences up to 6.2⋅1018 e/cm2 on the structural and dielectric properties of these crystals is studied; the dependence of crystal structure parameters on the fluences is considered; the structural mechanism of selective substitution of Pb by Sr is established. It is determined that the sites occupied by lead with a lone pair are not substituted by strontium cations. Up to the fluences of 6.2⋅1018 e/cm2, the (Pb0.86Sr0.14)5Ge3O11 structure remains perfect. It is shown that the irradiation with these fluences preserves the paraelectric structure at 293 K (P6 space group) and causes only minor atomic displacements. The temperature dependences of the dielectric permittivity and the dielectric loss (in the ranges of 5-300 K and 1-1000 kHz) show that the irradiation shifts TC from 158 K to 145 K and increases the diffusion of the ferroelectric phase transition.
