Re-entrant type relaxor behavior in (1−x)BaTiO3–xBiScO3 solid solution

Abstract

The solid solution of (1−x)BaTiO3–xBiScO3 was synthesized by solid state reaction and its dielectric properties were studied by impedance spectroscopy. A dielectric anomaly was found in the temperature ranges of −30–13°C and −60–20°C for 0.95BaTiO3–0.05BiScO3 and 0.90BaTiO3–0.10BiScO3, respectively. The frequency dependence of the anomaly exhibits dielectric relaxation satisfying the Vogel–Fulcher law, indicating relaxorlike behavior. The relaxor state in the (1−x)BaTiO3–xBiScO3 solid solution occurs after the ferroelectric phase transition upon cooling, indicating a re-entering phenomenon. Piezoresponse force microscopic studies show that the domain wall density decreases with the addition of BiScO3. The substitution of BiScO3 also results in some no-phase-contrast areas in the domain structure image, which grow with the increasing BiScO3 amount. Decent piezoelectric hysteresis loops were obtained in these areas. The correlation between the peculiar domain structure and relaxor behavior suggests that the no-phase-contrast areas are characteristics of the domain structure of the re-entering relaxor system.