Multifunctional bismuth sodium titanate-based ferroelectric ceramics with bright red emission and large strain response

Abstract

In this paper, we systematically studied the structure and properties of SrPrAlO4-modified (Bi0.5Na0.5)0.935Ba0.065TiO3 (BNT-0.065BT) lead-free piezoelectric ceramics. There is no impurity in the SrPrAlO4-modified BNT-0.065BT, and all samples form pure perovskite structure. The substitution of SrPrAlO4 induces the transformation of ferroelectric to ergodic relaxor phase. As a result, a large electric-field induced strain of 0.35% (@70 kV/cm, corresponds to a large signal piezoelectric d33* (Smax/Emax) of 500 pm/V) is obtained when the SrPrAlO4 dopant concentration is 0.012. In addition, the large strain in this material is very resistant to field cycling, rendering the material attractive for its fatigue-free behavior. Moreover, SrPrAlO4-modified ceramics exhibit orange-red emission under 450 nm photoexcitation. There is a strong red emission peak at 610 nm corresponded to the transition of 1D2 →3H4 and a weak red emission peak at 660 nm ascribed to the 3P0 →3F2 transition. The multifunctional characteristics with good electrical and luminescent properties in BNT-0.065BT-xSrPrAlO4 ceramics render the materials may have broad application prospects in new devices with multiple functions.