Very-low temperature synthesis of pure and crystalline lead-free BCZT ceramic with enhanced dielectric properties

Lead-based ferroelectric materials, such as Pb(Zr,Ti)O3 (PZT) have been widely studied as a potential technological materials in electrical energy storage. Nevertheless, the high toxicity of lead can pollute environment, cause... [ view full abstract ]

Lead-based ferroelectric materials, such as Pb(Zr,Ti)O₃ (PZT) have been widely studied as a potential technological materials in electrical energy storage. Nevertheless, the high toxicity of lead can pollute environment, cause damage to brain and nervous system. Thus, due to environmental concern, an intensive research has been conducted to find the appropriate alternative to lead-based materials. A promising category of lead-free ceramic is the perovskite barium titanate (BaTiO₃). It has been the first practically used piezoelectric ceramics and still the widely employed in modern technologies for developing low-energy consumption devices like wireless sensors, actuators and self-powered nanogenerators. Moreover, BaTiO₃ is a bioceramic witch not contain any toxic or volatile element, and its properties can be easily tailored by site engineering. Based on this last characteristic, introducing new elements into the crystal lattice of BaTiO₃ can enhance the ferroelectric, dielectric and piezoelectric properties of these materials.

W. Liu and X. Ren have reported non-Pb ceramics of Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) with high dielectric constant (18 000) and piezoelectric coefficient (620 pC/N). This promising finding has created a great interest around site-doping, phase’s transitions, morphological engineering and sintering processes to develop BCT-BZT ceramic with highly enhanced ferroelectric and piezoelectric properties. Although, the most of these studies have suffered from high-energy consumption, contamination or production scale.

In this study, we reported for the first time a new strategy for the synthesis of pure and crystalline BCZT lead-free ferroelectric powders at very low temperature (Fig. 1). The effects of the preparation temperature on the structure, crystallinity, purity, morphology, particles size distribution and dielectric properties of BCZT powders were studied.