Ferroelectric properties of rare-earth oxides doped (K0.4Na0.6)0.95Li0.05(Nb0.95Sb0.05)O3 lead-free piezoceramics

The rare-earth oxides (Pr2O3 and Yb2O3)-doped (K0.4Na0.6)0.95Li0.05(Nb0.95Sb0.05)O3 [KNNLS] ceramics were prepared using conventional solid sintering method for improving the ferroelectric properties of KNN-based ceramics. The effects of rare-earth oxides on the crystal structure, microstructure, dielectric and ferroelectric properties of the ceramics were systematically studied. The Curie temperature (Tc) decreases slightly with the increase of Pr2O3 and Yb2O3. The results show that Pr2O3 and Yb2O3 can greatly enhance the ferroelectric properties of KNNLS. The KNNLS-0.1 mol% Pr2O3 ceramic and KNNLS-0.1 mol% Yb2O3 ceramic show excellent ferroelectric properties: Pr = 42.8 μC/cm2, Ec = 7.2 kV/cm and Pr = 37.3 μC/cm2, Ec = 12.8 kV/cm, respectively.