Enhanced electro-strain with high electrostrictive performances of Bi0.5Na0.4K0.1TiO3 based lead-free piezoelectric ceramics by Ba(Fe0.5Nb0.5)O3

• Published in: Materials research bulletin 2023-11, Vol.167, p.112417, Article 112417
• Main Authors: Jaita, Pharatree, Sanjoom, Ratabongkot, Rujijanagul, Gobwute
• Format: Article
• Language: English
• Subjects: Dielectric; Electro-strain; Electrostrictive; Ferroelectric; Lead-free piezoelectric ceramics
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2023.112417

•We fabricated [0.97BNKT-0.03BST]-BFN by a simple conventional mixed oxide.•The x = 0.01 ceramic had a large electric field-induced strain of 0.42% (846 pm/V).•The x = 0.01 ceramic presented a high electrostrictive coefficient (0.0432 m4/C2).•The x = 0.01 ceramic had large d*33 and Q33 at a moderate electric field of 50 kV/cm.•Suggesting [0.97BNKT-0.03BST]-BFN to be candidate for actuator applications. Complex piezoelectric ceramics of (1-x)[0.97(Bi0.5Na0.4K0.1)TiO3–0.03(Ba0.7Sr0.3)TiO3]-xBa(Fe0.5Nb0.5)O3 or (1-x)[0.97BNKT-0.03BST]-xBFN were investigated, where the x value was between 0 and 0.03. All compositions were synthesized via a conventional mixed oxide method. X-ray diffraction and Raman spectroscopy techniques indicated that all ceramics exhibited a coexistence of rhombohedral (R) and tetragonal (T) phases without any impurity phase. However, the T phase became dominant at higher BFN contents. The maximum temperature (Tm), the ferroelectric to ergodic relaxor phase transition temperature (TF-R), and Burn’s temperature (TB) decreased with increasing BFN content, while the dielectric constant at Tm was enhanced for the x = 0.01 ceramic. The BFN additive interrupted ferroelectric ordering, which led to constriction in the hysteresis loops as well as large electric field-induced strains (Smax = 0.42%), a normalized strain coefficient (d*33 = Smax/Emax = 846 pm/V), and an electrostrictive coefficient (Q33 = 0.0432 m4/C2) for the x = 0.01 ceramic under a moderate applied electric field of 50 kV/cm. These results indicated that this ceramic had the potential for electromechanical applications. [Display omitted]