Effect of lanthanum doping on the structural, ferroelectric, and strain properties of Bi1/2(Na0.82K0.18)1/2TiO3 lead-free ceramics

• Published in: Journal of the Korean Physical Society Vol. 62; no. 7; pp. 1004 - 1008
• Main Authors: Dinh, Thi Hinh, Lee, Hyun-Young, Yoon, Chang-Ho, Malik, Rizwan Ahmed, Kong, Young-Min, Lee, Jae-Shin, Tran, Vu Diem Ngoc
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.04.2013; 한국물리학회
• Subjects: Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; 물리학; Electric-field-induced strain; Lead-free piezoelectric; Relaxor; Bismuth sodium titanate; La doping
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.62.1004

To clarify the effect of A-site donor doping on the phase transition and the strain enhancement, we investigated the crystal structure, as well as the piezoelectric, ferroelectric and electric-field-induced strain (EFIS) properties of La-doped Bi 1/2 (Na 0.82 K 0.18 ) 1/2 TiO 3 (BNKT) ceramics. Similarly to our previous studies on BNKT doped with B-site donors such as Nb and Ta, La doping was found to induce a ferroelectric-to-nonpolar (FE-NP) phase transition, leading to a large enhancement in EFIS just after the transition. The result provides strong evidence that a close relationship exists between the Goldschumidt’s tolerance factor and the FE-NP transition in BNKT, which has been observed in B-site-donor or isovalent impurity-doped BNKT.