Microstructure and electrical properties of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃- (Ba_0.85Ca_0.15)TiO₃ lead-free piezoelectric ceramics

The (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃-5%(Ba_0.85Ca_0.15)TiO₃(BCZT-5%BCT) lead-free piezoelectric ceramics were prepared by the tape casting process and sintered at 1 500 ℃ with different soaking time. The effects of the microstructure of BCZT-5%BCT ceramics on the electrical properties of BCZT-5%BCT ceramics were studied. The results show that the grain size of BCZT-5%BCT ceramics has significant effect on its piezoelectric, dielectric and ferroelectric properties. When it was sintered at 1500 ℃, the grain size of BCZT-5%BCT ceramics was increased first and then decreased with the increase of the sintering time. The grain size of the sample was the maximum at the sintering time of 8h, while the piezoelectric and ferroelectric properties of BCZT-5%BCT ceramics were the optimum as the follows: d₃₃=218 pC/N, 2P_r=30.48 μC/cm², ε_r=1 617, tan δ=0.037, T_C=90.6 ℃.