Electric Properties of SrTiO3 Modified (Na0.48K0.48Li0.04)Nb0.89Ta0.05Sb0.06O3 Lead-Free Ceramics

In this paper, the effects of SrTiO3 are investigated by using the solid-state reaction method for (Na0.48K0.48Li0.04)Nb0.89Ta0.05Sb0.06O3 lead free ceramics (Na0.48-xK0.48-xLi0.04Srx)Nb0.89-xTixTa0.05Sb0.06O3). The structural, dielectric, piezoelectric, and ferroelectric properties are discussed in detail. When the amount of SrTiO3 dopants was increased, the phase transition temperature TO-T and Tc drastically decreased, and the phase coexistence of the orthorhombic and tetragonal phases occurred at x = 0.005-0.008, leading to a significant enhancement in the electric properties of the samples. The ceramics with x = 0.007 exhibited good electrical properties (d33 = 280 pCN−1, kp = 47%, ɛ = 1666, g33 = 19 (10−3Vm/N), d33 × g33 = 5202 (10−15m2/N), Pr = 15.1 μC/cm2, and Ec = 14.2 kV/cm) compared with the pure NKN-based samples (d33 = 226 pCN−1, kp = 44%, ɛr = 1250, tan δ = 3%, g33 = 20 (10−3Vm/N), d33 × g33 = 4615 (10−15m2/N), Pr = 9.25 μC/cm2, and Ec = 9.7 kV/cm). In particular, the tan δ loss of the proposed samples is only 2%, which is quite small compared to the reported data.