Phase transition and electrical characteristics of Bi0.5(Na0.78K0.22)0.5TiO3–BiFeO3 lead-free piezoelectric ceramics. Issue 8 (September 2015)

• Record Type: Journal Article
• Authors: Lee, Ku-Tak; Park, Jung-Soo; Cho, Jeong-Ho; Jeong, Young-Hun; Paik, Jong-Hoo; Yun, Ji Sun
• Is Part Of: Ceramics international. Volume 41:Issue 8(2015)
• Page Start: 10298
• Page End: 10303
• Publication Date: 2015-09
• Subjects: E. Actuator -- Lead free piezoelectric ceramics -- Phase transition -- Electric field-induced strain; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2015.04.063
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: A conventional, solid-state reaction method was used to fabricate lead-free piezoelectric ceramics (1− x )Bi0.5 (Na0.78 K0.22 )TiO3 – x BiFeO3 ((1– x )BNKT– x BF) with x =0–0.09. The XRD patterns of the BNKT–BF ceramics confirmed a phase transition from tetragonal to pseudo-cubic phase with increasing BF content. The secondary ceramic phase was found in 0.91BNKT–0.09BF ( x =0.09) ceramics. As the BF content increased, the ferroelectric order was disrupted, resulting in decreased remnant polarization, coercive field, and ferroelectric-to-relaxor transition temperature. This led simultaneously to the improvement of the electric-field-induced strain. The largest electric-field-induced strain ( S max =0.35% at 5 kV/mm) and the highest normalized strain value ( d 33 ⁎ = S max / E max =676 pm/V) were obtained with 0.97BNKT–0.03BF ( x =0.03) ceramics. The behavior at the point of phase transition is discussed.