Abstract: (1-x)(Na_1/2Bi_1/2)TiO₃-xBaTiO₃ (x=0.06) with 1-5 at% lanthanum was prepared by the conventional mixed oxide method. The
effect of La³⁺ doping on dielectric behavior and piezoelectric properties of the ceramics was studied. The relaxor behavior of the La³⁺
doped ceramics is more evident. At room temperature, the dielectric constant is increased. When the La content is less than 1.5 at%, the piezoelectric
properties are enhanced. But in the meantime the dielectric loss of the ceramics is also increased. When the content of La³⁺ is up to 3 at%,
the ceramics’ piezoelectric properties are remarkably debased.

Key words: （Na_1/2Bi_1/2）TiO₃, lead-free piezoelectric ceramics, relaxor, diffuse phase transition