A strategy for obtaining high electrostrictive properties and its application in barium stannate titanate lead-free ferroelectrics

Recently electrostrictive effect in ferroelectrics has attracted much attention, since the electric field-induced strain based on such an effect possesses an ultra-low hysteresis, which is of special interest to both fundamental research and potential application in high-precision actuators. In this paper, we propose a strategy to obtain high electrostrictive properties in ABO₃ perovskite structure BaTiO₃ (BT)-based ferroelectric ceramics by means of doping. The doping element, amount, valence as well as position are specified according to this strategy. It is suggested that B-site Sn⁴⁺-doped BT, i.e., Ba(Ti_1-xSn_x)O₃ (BTS), would possess superior electrostrictive properties. The structural evolution and electrical properties of BTS ferroelectric ceramics were investigated in detail in order to verify this deduction. Besides the ferroelectric-to-relaxor transition with respect to the increase of x from 0.06 to 0.11, expected and high electric field-induced strain (> 0.08% at 40 kV/cm) with a very ultra-low hysteresis (< 8%) is obtained in x = 0.10–0.11 compositions. High longitudinal electrostrictive coefficient Q₃₃ ranges from to 0.0398 m⁴/C² to 0.0515 m⁴/C² accompanying with temperature- and composition-insensitive characteristics. These results not only prove the effectiveness of this strategy, but also pave a way to search for novel kinds of electrostrictive systems in ferroelectrics.