Effect of High-Energy Electron Irradiation on the Structural, Dielectric, and Nonlinear Optical Properties of Single Crystals of Pb 5 (Ge 1– х Si x ) 3 O 11 (0 ≤ x ≤ 0.55) Solid Solutions

Stoichiometric single crystals of Pb 5 (Ge 1– х Si x ) 3 O 11 solid solutions (0 ≤ x ≤ 0.55) are obtained by slow cooling of 5PbO·3(1– y )GeO 2 ·3 y SiO 2 melts. The chemical analysis confirms their cation and anion stoichiometry. The effect of their high-energy (10 MeV) electron irradiation with fluences from 0.1·10 18 e/cm 2 to 4.39·10 18 e/cm 2 on the structural, ferroelectric, and nonlinear optical characteristics of the crystals is studied for the first time. The dependence of crystals on concentrations and fluences is detected. According to the date of dielectric spectroscopy and second harmonic generation of laser radiation, the doping with Si causes a systematic shift of T c to low temperatures, a decrease in the peak value of the dielectric permittivity, and a noticeable phase transition smearing with transforming to the zelaxor ferrollectric state of x = 0.35. According to the structural studies of initial and irradiared, Pb 5 (Ge 1– x Si x ) 3 O 11 crystals, they retain the structural perfectness without any signs of amorphization. Structural distortions of Pb 5 (Ge 1– x Si x ) 3 O 11 do not significantly depend on the fluence.