Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/30374
Title: Structure, electrical properties and temperature characteristics of Bi0.5Na0.5TiO3-Bi0.5K0.5TiO3-Bi0.5Li0.5TiO3 lead-free piezoelectric ceramics
Authors: Lin, D
Zheng, Q
Xu, C
Kwok, KW 
Issue Date: 2008
Publisher: Springer
Source: Applied physics. A, Materials science & processing, 2008, v. 93, no. 2, p. 549-558 How to cite?
Journal: Applied physics. A, Materials science & processing 
Abstract: (1-x-y)Bi0.5Na0.5TiO3-xBi(0.5)K(0.5)TiO(3)- yBi(0.5)Li(0.5)TiO(3) lead-free piezoelectric ceramics have been prepared by an ordinary sintering technique, and their structure, electrical properties, and temperature characteristics have been studied systematically. The ceramics can be well-sintered at 1050-1150 degrees C. The increase in K+ concentration decreases the grain-growth rate and promotes the formation of grains with a cubic shape, while the addition of Li+ decreases greatly the sintering temperature and assists in the densification of BNT-based ceramics. The results of XRD diffraction show that K+ and Li+ diffuse into the Bi0.5Na0.5TiO3 lattices to form a solid solution with a pure perovskite structure. As x increases from 0.05 to 0.50, the ceramics transform gradually from rhombohedral phase to tetragonal phase and consequently a morphotropic phase boundary (MPB) is formed at 0.15 <= x <= 0.25. The concentration y of Li+ has no obvious influence on the crystal structure of the ceramics. Compared with pure Bi0.5Na0.5TiO3, the partial substitution of K+ and Li+ for Na+ lowers greatly the coercive field E-c and increases the remanent polarization P-r of the ceramics. Because of the MPB, lower E-c and large P-r, the piezoelectricity of the ceramics is improved significantly. For the ceramics with the compositions near the MPB (x=0.15-0.25 and y=0.05-0.10), the piezoelectric properties become optimum: piezoelectric coefficient d(33)=147-231 pC/N and planar electromechanical coupling factor k(P)=20.2-41.0%. In addition, the ceramics exhibit relaxor characteristic, which probably results from the cation disordering in the 12-fold coordination sites. The depolarization temperature T-d shows a strong dependence on the concentration x of K+ and reaches the lowest values at the MPB. The temperature dependences of the ferroelectric and dielectric properties at high temperatures may imply that the ceramics may contain both the polar and non-polar regions at temperatures above T-d.
URI: http://hdl.handle.net/10397/30374
ISSN: 0947-8396
EISSN: 1432-0630
DOI: 10.1007/s00339-008-4667-z
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

32
Last Week
0
Last month
1
Citations as of Oct 16, 2017

WEB OF SCIENCETM
Citations

28
Last Week
0
Last month
1
Citations as of Oct 15, 2017

Page view(s)

53
Last Week
6
Last month
Checked on Oct 15, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.