Enhanced piezoelectric properties of 0.49Pb(Ni,Nb)O3-0.51Pb(Hf,Ti)O3ceramics by ion pair doping

Based on the relaxation ferroelectric of 0.49Pb(Ni1/3Nb2/3)O-3-0.51Pb(Hf0.3Ti0.7)O-3(0.49PNN-0.51PHT), the method generating structural defects by Li(+)and Al(3+)ion pair doping was proposed to improve the piezoelectric property. Results showed that the ion pairs facilitated the increase of tetragonal phase content in perovskite structure, and caused larger lattice distortion along the [001] direction. A high piezoelectric coefficient ofd(33) = 1040 pC/N was achieved for the 0.49PNN-0.51PHT ceramic when the doping content was 0.4 at.%, with better piezoelectric response. Also, the reason improving piezoelectric properties was further analyzed by impedance spectra. The findings indicate that constructing such defect pairs can efficiently improve the piezoelectric properties of relaxed ferroelectrics.