Enhancing piezoelectric coefficient d33 in LiF-doped BaTiO3 ceramics by optimizing excess Ba content

The excess Ba adding in BaTiO3-0.04LiF ceramics effectively suppressed the grain growth. The grain sizes decrease from 22 μm at x = 0 to 10 μm at x = 0.025 in Ba1+xTiO3-0.04LiF ceramics, and then increase to 18 μm at x = 0.04 which was caused by the emergence of impurity phase. The maximum d33 = 340 pC/N was achieved in the ceramic of x = 0.025, which is mainly contributed to the smallest grain size about 10 μm.