Correlation Between Microstructure and Electric Behavior of (1−x)Ba0.96Ca0.04TiO3-xBa(Mg1/3Nb2/3)O3 Ceramics Prepared via Chemical-Furnace-Assisted Combustion Synthesis

The (1−x)Ba0.96Ca0.04TiO3-xBa(Mg1/3Nb2/3)O3 (x = 0–0.20) lead-free ceramics were prepared through the chemical-furnace-assisted combustion synthesis (abbreviated as CFACS). The phase structure, microstructure, dielectric, and piezoelectric properties were systematically investigated. Phase analysis revealed the coexistence of orthorhombic and tetragonal phases in the vicinity of x = 0.07. More importantly, the composition with x = 0.07 exhibited optimal overall electrical properties, including a high piezoelectric coefficient (d33) of 495 pC/N, the planar electromechanical coupling factor (Kp) of 41.9%, and the Curie temperature (Tc) of 123.7 °C. In addition, the average grain size was observed to progressively decrease with increasing x.