Lead-free multifunctional ceramics with superior electric-field-induced strain and photoluminescence properties

0.93Bi0.5Na0.5TiO3−0.07BaTiO3−xPr (BNT-BT-xPr, x = 0, 0.4, 0.8, 1.2 and 1.6 mol%) multifunctional ceramics were prepared using the solid-state reaction method. Electric field dependent strain behavior and photoluminescence properties of this system have been investigated. It was found that the replacement of Bi by Pr induced a ferroelectric-relaxor phase transition with the degradation of the long-term ferroelectric properties. At the phase transition point, the electric-field-induced strain was significantly enhanced and reached the highest strain value of 0.43% (70 kV/cm, corresponds to a d33* = 566 pm/V) at 1.2 mol% Pr addition. Besides the excellent strain properties, Pr-modified BNT-BT materials exhibited a bright photoluminescence with a strong orange emission located at around 612 nm owing to the 1D2 → 3H4 transition under the 468 nm light excitation at room temperature. These findings suggest that this material is a good candidate for developing multifunctional optoelectronic devices.