An in~situ structural description of the origin of the ferroelectric properties as a function of the applied electric field E was obtained by synchrotron x-ray diffraction. A setup was used to average the effects of the preferred orientation induced by the strong piezoelectric strain and solve in~situ the crystal structure as a function of the applied electric field. Hence, we were able to describe the microscopic origin of the macroscopic ferro- and piezoelectric properties of the most widely used ferroelectric material, lead zirconate titanate.

Hybrid inorganic–polymer nanocomposites can be employed in diverse applications due to the potential combination of desired properties from both the organic and inorganic components. The use of novel bottom–up in situ synthesis methods for the fabrication of these nanocomposites is advantageous compared to top–down ex situ mixing methods, as it offers increased control over the structure and properties of the material. In this review, the focus will be on the application of the sol–gel process for the synthesis of inorganic oxide nanoparticles in epoxy and polysiloxane matrices. The effect of the synthesis conditions and the reactants used on the inorganic structures formed, the interactions between the polymer chains and the inorganic nanoparticles, and the resulting properties of the nanocomposites are appraised from several studies over the last two decades. Lastly, alternative in situ techniques and the applications of various polymer–inorganic oxide nanocomposites are briefly discussed.

Temporal behavior of ferroelectric ceramics during the polarization switching cannot be satisfactorily explained by simple Debye or even stretched exponential laws. These materials exhibit rather a wide spectrum of characteristic times interpreted by different authors as switching or nucleation waiting times, the physical reasons for a wide time distribution still remaining unclear. A new model of polarization switching presented here suggests that the characteristic time variance in the ferroelectrics originates from the random distribution of the local electric fields due to intrinsic randomness of the material. The presented theory allows a direct extraction of the distribution of field values from the experiment. Systematic studies of polarization switching in fatigued lead zirconate titanate demonstrate the evolution of the field distribution with increasing level of fatigue. Plausible cause of the formation of regions subject to different field strengths is the generation of defects such as microcracks, pores, or voids in the course of fatigue. Suitability of the proposed model is demonstrated by an excellent correlation between experimental and calculated data for virgin and differently fatigued samples in a broad time-field region covering the electric field values of 0.5\char21{}2.5 kV/mm and nine orders of the magnitude of poling time.