Effect of Li{sub 2}CO{sub 3} addition on the dielectric and piezoelectric responses in the low-temperature sintered 0.5PZN-0.5PZT systems

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2800264· OSTI ID:21064416

Yudong, Hou; Limin, Chang; Mankang, Zhu; Xuemei, Song; Hui, Yan ^[1]

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1. Department of Materials Science and Engineering, Beijing University of Technology, Beijing 100022 (China)

Low-temperature sintering of 0.5Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-0.5Pb(Zr{sub 0.47}Ti{sub 0.53})O{sub 3} ceramics (0.5PZN-0.5PZT) was investigated using Li{sub 2}CO{sub 3} as sintering aids. The addition of Li{sub 2}CO{sub 3} significantly improved the sinterability of 0.5PZN-0.5PZT ceramics, resulting in a reduction of sintering temperature from 1100 to 950 deg. C. Moreover, the effect of Li{sub 2}CO{sub 3} addition on the dielectric and piezoelectric responses in 0.5PZN-0.5PZT systems was systematically studied in this work. The analysis of x-ray diffraction patterns and scanning electron microscopy indicated that the solubility limit of Li ions in perovskite structures was near 0.5 wt % in Li{sub 2}CO{sub 3} form. Below the solubility limit, Li{sup +} ions entered the six-fold coordinated B sites of oxygenic octahedral center and enhanced the compositional fluctuation in nanoscale, resulting in the increase of the degree of diffuseness {gamma}. While at high doping level above the solubility limit, {gamma} decreased subsequently, which was attributed to the formation of pyrochlore phase. Raman analysis on the B-site cation order correlates well with the dielectric measurement results. The large improvements in the piezoelectric properties such as the coupling factor and piezoelectric constant were also observed for doped specimens. Optimized parameters, such as d{sub 33}=278 pC/N, k{sub p}=0.50, and {epsilon}{sub max}=8800, were achieved by doping 0.5 wt % Li{sub 2}CO{sub 3} in low-temperature sintered 0.5PZN-0.5PZT systems, which shows great promise as practical materials for multilayered piezoelectric device applications. The observed improvement in the electric properties can be attributed to the grain size effect. After doping, the clamping effect caused by oxygen vacancies and grain boundary phases on domain wall motion was largely reduced due to the increase of grain size; therefore, a significant reduced coercive field and an increased remanent polarization were observed in doped 0.5PZN-0.5PZT systems.

• OSTI ID: 21064416
• Journal Information: Journal of Applied Physics, Vol. 102, Issue 8; Other Information: DOI: 10.1063/1.2800264; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERAMICS
DIELECTRIC MATERIALS
DOPED MATERIALS
GRAIN BOUNDARIES
GRAIN SIZE
LITHIUM CARBONATES
LITHIUM IONS
NANOSTRUCTURES
NIOBATES
PIEZOELECTRICITY
PYROCHLORE
PZT
RAMAN SPECTRA
SCANNING ELECTRON MICROSCOPY
SINTERING
SOLUBILITY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 1000-4000 K
VACANCIES
X-RAY DIFFRACTION