The results of the investigations on (1 — x)PMN-xPT ceramic samples obtained by sol—gel (SG) technology are presented in this study. In the (1 — x)PMN-xPT samples, the temperature Tm (at which real part of dielectric permittivity reaches its maximum) increases from ~270 K for x = 0 to ~500 K for x = 0.5. At room temperature, the samples with low values of x exhibit relaxor properties, while with increasing x the transition to normal ferroelectric properties takes place. Usually 0.9PMN-0.1PT or 0.925PMN-0.075PT solid solutions are considered as boundary compositions between relaxor and ferroelectric properties at room temperature.This study presents the analysis of X-ray diffraction patterns, fracture microphotographs, electromechanical parameters, and hysteresis loops for ceramics obtained from SG PMN—PT powders densified by the hot pressing method with a composition range, x = 0—0.37.

The thermodynamic state of a triglycine sulphate crystal, previously exposed to an electric field parallel to the non-ferroelectric c-axis, has been investigated. The frozen ferroelectric c-domains have been observed by a liquid crystal technique and under the scanning electron microscope. Pyroelectric properties and polarization in the non-ferroelectric direction have been investigated. Regions of dipoles that are strongly correlated along the c-direction as well as the clamping of the b-polarization switching have been found to be accompanied by permanent transverse polarization.

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