Lead-free Bi_1/2(Na_0.82K_0.18) _1/2TiO₃ ceramics exhibiting large strain with small hysteresis

This work attempted to reduce hysteresis in electric field-induced strain properties of lead-free Bi_1/2(Na_0.82K_0.18) _1/2TiO₃ceramics by modification with a (Ba,Ca)ZrO ₃(BCZ) solid solution. It was found that BCZ induced a phase transition from a ferroelectric state to a relaxor, resulting in a large strain at the transition region like other previous reports on Bi-based ceramics. Although previous works on Bi-based ceramics reported the normalized strain over 600 pm/V with large hysteresis over 50%, BCZ modified BNKT showed a much lower hysteresis of 25% while maintaining a large normalized strain of 549 pm/V, which is believed to open a new road to further reduce the strain hysteresis in Bi-based lead-free relaxors.