Low electric field-induced strain and large improvement in energy density of (Lu0.5Nb0.5)4+ complex-ions doped BNT-BT ceramics

The (Bi0.5Na0.5)(0.94)Ba0.06Ti(1-x)(Lu0.5Nb0.5)(x)O-3 (BNBT-xLN, x=0, 0.02, 0.03, 0.04, 0.05, 0.07) ceramics were designed to investigate their dielectric, ferroelectric, energy storage and electrostriction properties. All ceramics illustrated single pseudo-cubic perovskite structure and densely stacked microstructure. The LN doping disturbed the long-range ordered ferroelectric phase, which was confirmed by the depressed P-I-E loops and S-E curves. The excellent piezoelectric response was realized in the coexistence region of the ferroelectric polar and weak-polar phases. A significant enhancement of electric field-induced strains (S-max=0.42%) with a large average normalized strain coefficient (d(33)(*)=S-max/E-max) of 602.41pm/V, electrostriction coefficient (Q(33)=0.0334m(4)/C-2) was achieved at x=0.02. And a high energy storage density of 0.72J/cm(3) was obtained at x=0.03. As a result, the systematic investigations on the BNBT-xLN ceramics can benefit the developments of low electric field piezoelectric and energy storage devices.