2.1. Synthesis and Characterization of BCZT

The Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ and Ba_0.9Ca_0.1Zr_0.1Ti_0.9O₃ ceramic powders were prepared by using the solid-state reaction method. The starting materials were BaCO₃ (99%, Sigma-Aldrich, St. Louis, MO, USA), CaCO₃ (98.5–100.5%, Sigma-Aldrich), ZrO₂ (99%, Sigma-Aldrich), and TiO₂ (99%, Sigma-Aldrich) oxide powders. The oxide powders were weighed according to stoichiometric formulae, mixed using ethanol as a solvent, and ball-milled for 24 h. The slurry was dried at 100 °C for 24 h and sieved. The mixed compounds were calcined at different temperatures and dwell times at 1200 and 1250 °C for 2 and 4 h, respectively. Subsequently, the powder was uniaxially pressed into green pellets 10 mm in diameter and 1 mm in thickness at a one-ton compression. Finally, the samples were sintered at 1450 °C for 4 h. The phase formation of ceramic powder was observed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and the intercept method were used to examine the microstructure and grain size, respectively. To characterize the dielectric and ferroelectric properties, the surfaces of the sintered samples were polished and coated with silver paste on both sides to serve as electrodes.