Relaxor–ferroelectric crossover seen via characteristic temperatures of BaxSr1–xTiO3 ferroelectrics detected by acoustic emission

Abstract

BaxSr1–xTiO3 ferroelectrics ceramic with x = 70 and 80% have been studied by means of acoustic emission over a wide 0–300 °C temperature range and under dc external electric field. All the Curie temperatures Tc, intermediate temperatures T*, and Burns temperatures Td have been successfully detected and compared with those previously detected in BaxSr1–xTiO3 with x = 60% and pure BaTiO3, using the acoustic emission. For all the compounds, the critical end points at which the strains are expected to be largest, have been successfully detected, too. While the Tc linearly increases as x increases, it was established that both the T* and Td exhibit nonlinear behavior: they initially decrease, attain the minima near x ≈ 70% and then start to increase and tend to those, corresponding to pure BaTiO3, as it was previously reconstructed for Td in BaZrxTi1–xO3 compound [Shvartsman and Lupascu, J. Am. Ceram. Soc. 95, 1 (2012)]. Such a phenomenon is discussed from the viewpoint of the presence of polar nanoregions, intrinsic to pure BaTiO3 in the paraelectric phase, and it is concluded, that a minimum in both the T*(x) and Td(x) dependences points out a range of relaxor–ferroelectric crossovers in Ba‐based compounds.