Structural, dielectric, and ferroelectric properties of lead-free BCZT ceramics elaborated by low-temperature hydrothermal processing

Lead-free Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) ceramics have demonstrated excellent dielectric, ferroelectric, and piezoelectric properties in comparison to lead-based materials. The synthesis of pure and crystalline BCZT nanopowders at low temperatures of 25, 80, and 160 °C was reported previously by using a sol–gel method followed by a hydrothermal route. In this study, the structural, dielectric, and ferroelectric properties of sintered BCZT ceramics at 1250 °C/10 h were investigated. XRD measurements revealed the presence of a single perovskite phase at room temperature with the coexistence of the orthorhombic and tetragonal symmetries. The increase of grain size and the ceramic density in BCZT ceramics result in an enhancement of the dielectric and ferroelectric properties of BCZT ceramics. More interestingly, the synthesis temperature of BCZT powders with high dielectric and ferroelectric properties could be decreased to a low temperature of 160 °C, which is about 1200 °C lower when compared with solid-state reaction and 840 °C lower when compared with sol–gel methods. The BCZT ceramics elaborated at 160 °C revealed excellent electrical properties (dielectric constant, dielectric loss, remnant polarization, and maximal polarization of 12,085, 0.017, 8.59 µC/cm2, and 27.21 µC/cm2, respectively) and enhanced energy performances (recovered energy density and energy efficiency of 367.2 mJ/cm3 and 67.2%, respectively). Hence, the use of low-temperature hydrothermal processing can be encouraging for the synthesis of lead-free ceramics with high dielectric and ferroelectric properties