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

Abstract

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.