Piezoelectric and dielectric properties of Sb2O3 doped (Na0.84K0.16)0.5Bi0.5TiO3 lead-free ceramics

Sb2O3 doped (Na0.84K0.16)(0.5)Bi0.5TiO3 lead-free piezoelectric ceramics were fabricated by traditional ceramic technique. XRD results show that all compositions can form pure perovskite solid solution in the range of 0.1 wt%-0.6 wt% Sb2O3, which means the Sb2O3 can enter into the lattice effectively. The dielectric constant vs temperature patterns show that there are two peaks in the heating process which corresponding to the ferroelectric-antiferroelectric and antiferroelectric-paraelectric phase transitions. The broader dielectric peaks also indicates the ceramics have relaxor ferroelectric characteristics. The piezoelectric properties of (Na0.84K0.16)(0.5)Bi0.5TiO3 ceramic have been improved by doping Sb2O3. The piezoelectric constant d(33) = 124 pC/N is the maximum of all the compositions, and the planar electromechanical coupling factor k(p) is 24.87 %. The dielectric constant epsilon(T)(33)/epsilon(0) and dielectric loss tanb increase with the augment of dopant Sb2O3.