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The self-polarization effect in ferroelectric thin films has been studied for PZT films 0.5-1 µm thick deposited by radio-frequency magnetron sputtering of various ferroelectric ceramic targets (Zr/Ti = 54/46, Zr/Ti = 54/46 + 10% PbO and Zr/Ti = 40/60 + 10% PbO). The laser intensity modulation method has been applied, together with the methods of C-V characteristics and dielectric hysteresis loops, to determine the polarization distribution and evaluate the built-in electric fields in the films. It is shown that the bottom interface of the thin-film Pt-PZT-Pt capacitor structure is the source of self-polarization for a certain technological sequence of structure formation. The self-polarization effect is caused by two factors: (i) n- or p-type conductivity due to oxygen or lead vacancies or other impurities in the films and (ii) high trap density at the bottom interface of the structure.

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The dielectric properties, birefringence, domain structure, electrooptic and pyroelectric effects, specific heat and electroacoustic echo have been investigated in Cd2Nb2O7 at successive phase transitions. Physical properties in different phases have been discussed. The thermoactivated reorientations of polarization at the diffuse phase transition temperatures contribute not only to ε, electrooptic and pyroelectric effects, but also influence the electroacoustic echo relaxation time due to the spectral diffusion mechanism.

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