Structural, dielectric and ferroelectric properties of Cu2+- and Cu2+/Bi3+-doped BCZT lead-free ceramics: a comparative study

Perovskite-type Ba0.98Ca0.02Zr0.02Ti0.98O3 (BCZT), Ba0.98Ca0.02Zr0.02Ti0.976Cu0.008O3 (BCZTC) and Ba0.9725Bi0.005Ca0.02Zr0.02Ti0.976Cu0.008O3 (BCZTCB) lead-free ceramics were synthesised via solid-state reaction method at a sintering temperature of 1380 °C. Effects CuO Bi2O3/CuO doping on structural, microstructural, dielectric ferroelectric properties investigated systematically. X-ray diffraction technique confirmed the existence pure perovskite phase with tetragonal structure in doped BCZT room temperature. The analysis demonstrated two anomalies around 24 °C 126 for BCZT, which identified as orthorhombic to (TO-T) cubic (TC) transition temperature, respectively. TO-T shifted below 16 °C, while TC increased 132 BCZTCB sample. physical mechanisms conduction processes through impedance spectroscopy, values resistance, conductivity activation energies associated grain boundaries evaluated. energy was determined be higher samples than BCZT. Further, dopant-dependent nature ceramic evidenced by characteristic hysteresis loop, value remnant polarization (Pr = 4.59 μC/cm2) obtained Furthermore, d33 value, 54 pC/N 140 64 BCZTC BCZTCB,