Journal of the American Ceramic Society, Vol.103, No.3, 1765-1772, 2020
Giant electro-strain in textured Li+-doped 0.852BNT-0.11BKT-0.038BT ternary lead-free piezoelectric ceramics
Texturing is an effective approach to improving the piezoelectricity of piezoelectric ceramics. In this work, textured Li+-doped 0.852Bi(0.5)Na(0.5)TiO(3)-0.11Bi(0.5)K(0.5)TiO(3)-0.038BaTiO(3) ternary lead-free piezoelectric ceramics are prepared by the reactive templates grain growth (RTGG) method. X-ray diffraction (XRD) results demonstrate a high orientation degree of 77% along the direction. Outstanding electro-strain response, which is higher than most of reported BNT-based textured ceramics, is achieved due to the contribution of oriented-grains along the direction. A large electro-strain of 0.55% with a relatively low hysteresis is obtained at 6.5 kV/mm with corresponding large signal piezoelectric coefficient (d33*) of 846 pm/V in the textured ceramics, which is 49% higher than that of the random ceramics. Besides, the electro-strain could reach as high as 0.52%@5.5 kV/mm (d33* = 945 pm/V) at 100 degrees C. These results indicate that the RTGG is an effective way to design high performance lead-free piezoelectric materials.