DIELECTRIC SPECTRUM OF BATIO3 SINGLE-CRYSTALS

The dielectric spectra of BaTiO3 single‐domain and polydomain tetragonal crystals with 180° domain structure are investigated over the wide range of frequencies 103 to 1010 Hz. It is shown that the dielectric permittivity ε33 of the single‐domain crystals has three regions of dispersion including two regions of the high‐frequency relaxation. There is no relaxation contribution to the permittivity ε11 of the single‐domain crystals. In polydomain crystals the decrease of the low‐frequency dielectric permittivity and the increase of the high‐frequency one, due to the domain piezoelectric interaction, are observed. The results obtained are discussed from the point of view of the structural disorder in a real crystal. Conclusions are made concerning the ion potential relief character and the phase transition nature in BaTiO3. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA