Ferroelectric phase transitions in the BIMEVOX solid solutions

Ceramic solid solutions Bi4(V1-xMe x)2O11-y with x = 0 ÷ 0.3, Me = Zr, Ga, Fe were prepared by the solid state reactions and were studied by the DTA/DSC, X-ray diffraction, dielectric spectroscopy and the second harmonic generation (SGH) method. The temperature dependences of the SHG signal confirmed the noncentosymmetric structure of the samples with x ≤ 0.05 at room temperature. Similar features were observed in the SHG and dielectric property measurements, which give an indication of the strong domain walls pinning by oxygen vacancies inherent to the Bi4(V1-xMex)2O11-y structures.