Investigation of phase, structural, and electrical properties of BNT–BT solid solutions in the vicinity of MPB regime

Enhanced Electrostrictive Behavior in BNT-Based Ternary Piezoceramics via Antiferroelectric Domain Engineering

“…To accomplish this, researchers have introduced either a normal or an ergodic relaxor FE phase in the BNT-based system near the morphotropic phase boundary (MPB) regime. − In accordance with the Goldschmidt interpretation of MPB, the normal FE phase allows easy rotation of P vectors in external E , whereas the relaxor phase causes the P extension mechanism due to the formation of long-range ordered nanopolar regions (NPRs) . By incorporating both phases together in the BNT ceramics, a giant S was recorded near MPB. − For instance, normal FE phase BaTiO 3 (BT) in BNT near MPB exhibits S ∼ 0.16% at 67 kV/cm, whereas by adding the relaxor Bi­(Li 0.5 Ta 0.5 )­O 3 (BLT) in the BNT-BT solid solution (i.e., BNBT 0.0069 -0.008BLT), the S improves to ∼0.39% at 60 kV/cm . Similarly, in the Bi 0.5 Na 0.5 TiO 3 -Bi 0.5 K 0.5 TiO 3 (BNT-BKT) system, S ∼ 0.19% at 60 kV/cm has been reported, whereas the relaxor BiMg 0.5 Ti 0.5 O 3 (BMT) enhances the S up to 0.34% at 50 kV/cm in the composition of 72.5BNT-22.5BKT-5BMT (BNKMT). , On comparison among several BNT-based PE ceramics, BNKMT was found to exhibit excellent direct and converse PE characteristics simultaneously ( d 33 ∼ 180 pC/N and d 33 * ∼ 570 pm/V) that unveil its suitability for potential devices. , Additionally, the crystal structure of BNKMT is relatively unstable compared to other BNT-based piezoceramics because Bi 3+ loses the inert pair effect (i.e., oxidizes to a relatively unstable 5+ oxidation state).…”