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In this paper, the results of dielectric investigations on four different solid solutions of PbMg1/3Nb2/3O3‐PbSc1/2Nb1/2O3‐PbZn1/3Nb2/3O3 (PMN‐PSN‐PZN) are presented in a wide temperature range (from room temperature to 1100 K). At higher temperatures (above 600 K) and low frequencies, the electrical conductivity dominates in properties of these ceramics and the Maxwell–Wagner relaxation appears. The DC conductivity has some change in slope close to the Burns temperature. The value of conductivity activation energy is typical for oxygen vacancies conductivity. Close to the Burns temperature, anomalous behavior of the intrinsic dielectric permittivity is also observed due to the appearance of dielectric relaxation in the terahertz frequency range caused partially by dynamics of polar nanoregions and mainly by overdamped optical soft mode which softens toward T*. [ABSTRACT FROM AUTHOR]

The dielectric properties of CuCrO2 bulk and thin films are studied by evaluating the complex dielectric function ε. In addition to the small peak near the Néel temperature TN, a secondary broad peak is found at high temperatures around Tm=450 K≫TN. As a feature of relaxor ferroelectrics, the maximum temperature Tm increases with increasing frequency. The real part of ε decreases with increasing magnetic field h and the peak at TN vanishes. The secondary peak becomes smaller and is broadened with increasing magnetic field. ε increases with increasing film thickness. Near Tm, the dielectric function offers a critical behavior expressed by an exponent γ=1.74. Using scaling arguments, critical exponents β=0.13 and δ=13.38 are deduced. The exponents depend on the film thickness. While β increases, the exponent γ is reduced with increasing film thickness. [ABSTRACT FROM AUTHOR]