Preparation, microstructure, piezoelectric and ferroelectric properties of piezoelectric ceramics with low-lead component

xPbTi_0.4716Zr_0.4834 (Mn_1/3Sb_2/3)_0.0450 O₃-(1-x) (K_0.485Na_0.485Li_0.03) NbO₃ [xPMS-(1-x)KNLN] ceramics with low-lead component were prepared by using conventional ceramics method. Microstructure, piezoelectric and ferroelectric properties of the low-lead ceramics with different stoichiometry x fabricated at varied sintering temperature were studied. The XRD patterns of the ceramics show that the microstructure of the ceramics transform from a coexistence state of pyrochlore and pseudo-cubic perovskite to tetragonal perovskite while sintering temperature increases. The SEM analysis shows that a liquid-phase formed by the (K_0.485Na_0.485Li_0.03) NbO₃ component appeared during the sintering process and while the sintering temperature increases the holes appeared on the surface of the ceramics and disappeared when the ceramics were sintered at even higher sintering temperature. The electric measurement results obtained show that xPMS-(1-x)KNLN ceramics possess good piezoelectric and ferroelectric properties, and when sintered at 1250°C, the xPMS-(1-x)KNLN ceramics with x=0.75 ceramic possess the properties of d₃₃=182pC/N, k_p=34.5%, T_C=165°C, P_r=21.2 μC/cm², E_c=1.47 kV/mm, ε_r=1879 and tanδ=0.92%.