Processing and electromechanical properties of (Bi0.5Na0.5)((1-1.5x))LaxTiO3 ceramics

Bismuth sodium titanate (Bi0.5Na0.5TiO3, BNT) with 0-6 at.% lanthanum was prepared by the conventional mixed oxide method. Each composition was calcined at 800-900 degrees C for 2-5 h to form a pure perovskite phase, Green pellets were sintered at 1050-1150 degrees C for 1-4 h to obtain dense ceramics with at least 95% of theoretical density. X-ray diffraction (XRD) showed phase distortion as lanthanum was added to this system, Meanwhile, a small amount of La was found to affect the grain size and had an influence on the poling conditions and electrical properties, The BNT-based composition with 1 at.% La doping provided a dielectric constant (K) of 560, a piezoelectric charge constant (d(33)) of 92 pC/N, and a hydrostatic piezoelectric coefficient (d(h)) of 72 pC/N.