Phase transition and electrical properties of (1 − x)(K1/2Na1/2)NbO3–xBi(Sc3/4Co1/4)O3 lead-free ceramics. Issue 16 (13th August 2015)

• Record Type: Journal Article
• Authors: Cheng, Hualei; Du, Hongliang; Zhou, Wancheng; Luo, Fa
• Is Part Of: Journal of materials research. Volume 30:Issue 16(2015)
• Page Start: 2467
• Page End: 2473
• Publication Date: 2015-08-13
• Subjects: (K1/2Na1/2)NbO3, -- phase transition, -- microstructure, -- electrical properties; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1557/jmr.2015.228
• Languages: English
• ISSNs: 0884-2914

Abstract

Abstract: Abstract : Lead-free ceramics (1 − x )(K1/2 Na1/2 )NbO3 – x Bi(Sc3/4 Co1/4 )O3 [(1 − x )KNN– x BSC] were prepared by the conventional solid-state sintering method. X-ray diffraction patterns show that the introduction of BSC into KNN system caused insignificant change in crystal structure. The composition with x = 0.015 has diphasic tetragonal and orthorhombic phases. Moreover, the grain size significantly dependent on the composition. The phase transition temperatures of orthorhombic–tetragonal ( T O–T ) and tetragonal–cubic ( T C ) decreased with increasing x from 0 to 0.025. The T O–T value of KNN–0.015BSC ceramic is close to room temperature, resulting in good electrical properties ( d 33 = 190 pC/N, k p = 40.3%, εr = 1494, tgδ = 0.026), with the Curie temperature T C = 321 °C. The combination of good piezoelectric properties and high T C makes these KNN–BSC ceramics suitable for elevated temperature piezoelectric devices.