Bi0.5Na0.5TiO3-based relaxor ferroelectric ceramic with large energy density and high efficiency under a moderate electric field
Lead-free relaxor ferroelectric ceramics of (1 − x)(0.6Bi0.5Na0.5TiO3–0.4Sr0.7Bi0.2TiO3)–xAgNbO3 were fabricated by a conventional mixed oxide route. The multifunction of AgNbO3 (AN) doping into the 0.6Bi0.5Na0.5TiO3–0.4Sr0.7Bi0.2TiO3 (BNT–SBT) matrix can be divided into two main aspects. First, it enhances the breakdown electric field (Eb) as a result of reduced grain size and increased resistivity. Second, it improves η via enhancing the relaxation behavior and stabilizing the antiferroelectric (AFE) phase. Eventually, we achieved a large Wrec of 3.62 J cm−3 and a high η of 89% simultaneously under a moderate electric field of 246 kV cm−1 as the doping ratio x of AgNbO3 equals 0.05. In addition, the same sample also exhibits excellent temperature stability and good frequency stability, suggesting that AgNbO3 doped BNT–SBT ceramics could be an ideal candidate in high energy storage capacitors.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry C HOT Papers