Relaxor induced performance tuning around morphotropic phase boundary in Ba0.86Sr0.14Ti0.94Sn0.06 modified BNT-based ceramics

Abstract

BNT-based piezoelectric ceramics exhibit excellent electrical properties at the morphotropic phase boundary (MPB) with a pivotal relaxation structure. Here, a MPB containing R (R3c) and T phases (P4bm) is formed via inducing Ba_0.86S_r0.14Ti_0.94Sn_0.06O₃ in BNT ceramics. Then, lowered polarization anisotropy is produced with many possible polarization directions, which is beneficial for high piezoelectric performance. In particular, an optimized and stabile piezoelectric constant (d₃₃ = 182 pC N⁻¹) is gained with a dominating R and lesser T phase below the depolarization temperature (T_f–r) due to high ferroelectricity. A large strain (S_uni = 0.426%) is observed when the T phase is dominant due to the transformation from a nonergodic relaxor (NR) to ergodic relaxor (ER) phase along with double-hysteresis loops while T_f–r drops to room temperature. Due to the easily switched domain of the ER phase, an improvement in temperature stability and an increase is revealed for strain under the thermal field and electric field, respectively. Thus, this article elaborates on the performance within the MPB region with a changed relaxor structure, promoting the further development of lead-free piezoelectric ceramic materials.