Dielectric, ferroelectric and electric field-induced strain behavior of Ba(Ti0.90Sn0.10)O3-modified Bi 0.5(Na0.80K0.20)0.5TiO3 lead-free piezoelectrics

• Main Authors: Jaita P., Watcharapasorn A., Cann D.P., Jiansirisomboon S.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-84894200272&partnerID=40&md5=f172c7cb5394163e14041655d60941c5; http://cmuir.cmu.ac.th/handle/6653943832/7329
• Institution: Chiang Mai University

Lead-free piezoelectric ceramics of (1 - x)Bi0.5(Na 0.80K0.20)0.5TiO3-xBa(Ti 0.90Sn0.10)O3 or (1 - x)BNKT-xBTS (when x = 0-0.20 mol fraction) were investigated. Optimum sintering temperature was found to be 1125 C at which all compositions had relative densities 98-99% of their theoretical values. All compositions exhibited a single perovskite structure. The unit cell size expansion was observed as BTS content increased. A slight reduction of grain size was noticeable when small amount of BTS was added. The BNKT-0.05BTS sample had a large electric field-induced strain (Smax) of 0.36% which corresponded to the normalized strain coefficient (d33â̂ -) of 649 pm/V. The highest piezoelectric coefficient (d 33 = 215 pC/N) with good dielectric (Ér = 1721, tan δ = 0.0724 and Tc = 333 C) and ferroelectric properties (Pr = 20.49 μC/cm2, Rsq = 0.87) were obtained for BNKT-0.10BTS sample, suggesting that this composition had a potential to be one of the promising lead-free piezoelectric candidates for further use in actual applications. © 2014 Elsevier B.V. All rights reserved.