Effects of different Sb addition on [(K0.44Na0.52) Li0.04](Nb0.9-XTa0.1Sbx)O3 lead-free piezoceramics

Lead-free piezoelectric (K_0.44Na_0.52Li_0.04)(Nb_0.9-xTa_0.1Sb_x)O₃ ceramics were prepared by traditional electrical ceramic technique. The effects of different Sb doping on the microstructure, phase, dielectric and piezoelectric properties were studied. The results indicate that the multielement niobate ceramics with higher piezoelectric properties can be fabricated from different Sb doping of Sb³⁺ or Sb⁵⁺. But the higher density piezoceramics with the Sb³⁺ dopant was obtained, and less influenced by the compositions. In this system orthorhombic-tetragonal morphotropic phase boundary (MPB) composition range of 0.03< times <0.05 was revealed by the X-ray diffraction analysis, and the piezoelectric properties of the (K_0.44Na_0.52Li_0.04)(Nb_0.9-xTa_0.1Sb_x)O₃ is the best near the MPB composition range, and are rather sensitive to the phase compositions: dopant of Sb₂O₃ with the value at x= 0.04, d₃₃=248 pC/N, P_r=19.2 muC/cm², E_c=16.2 kV/cm, Q_m=31, epsiv_r=1254, k_p=0.41;dopant of Sb₂O₅ with the value at x= 0.05, d₃₃=253 pC/N, P_r=15.5 muC/cm², E_c=14.2 kV/cm.