LAUSR

Abstract Crystal structure, dielectric and piezoelectric properties of PLZT x/59/41 ceramics with 1 wt% Sb 2 O 5 addition were studied systematically by X-ray diffraction and electrical measurements. X-ray diffraction analyses show that the crystal structure experiences a phase transition from rhombohedral to tetragonal as the La content increasing. The piezoelectric charge coefficient d 33 increases dramatically as the La content increases from 5 mol% to 6.5 mol%. In the 6.5/59/41, the crystal structure is a mixture of cubic and tetragonal phases and the sample possesses a high piezoelectricity of d 33  = 821 pC/N. Meanwhile, the dielectric response exhibits a strong frequency-dispersion not only before poling but also after poling below the depolarization temperature, indicating that domains remain at nanoscale all the time in 6/59/41 and 6.5/59/41 samples. Considering the continuity of dispersive behaviors, it is suggested that the nanodomains after poling are coupled in a metastable state and are probably responsible for the high piezoelectricity.