Enhanced piezoelectric properties of Lu2O3 doped BCTS ceramics with orthorhombic-tetragonal coexisting phase

xLu(2)O(3)-(1-x)Ba0.98Ca0.02Ti0.96Sn0.04O3 ceramics were synthesized by a solid-phase reaction method. XRD phase analysis reveals that all samples have perovskite structures with orthorhombic-tetragonal coexisting phases. Grain sizes decrease and become more uniform with increasing Lu2O3 contents. Piezoelectric coefficient d(33) increases with appropriate Lu2O3 contents and attains a peak value of 598 pC/N at molar ratio (x = 0.0050) of Lu2O3, the high value of piezoelectric coefficient for BaTiO3 based ceramics reported in recent years. d(33) of xLu(2)O(3)-(1-x)Ba0.98Ca0.02Ti0.96Sn0.04O3 ceramics at x = 0.0050 is 111% higher than that of pure BCTS ceramics. The maximum value of residual polarization P-r (10.2 mu C/cm(2)) also occurs at x = 0.0050, remarkably improving d(33) with appropriate Lu2O3 contents.