Dielectric and piezoelectric properties in fluoride-doped PMNT ceramics
The effect of fluoride (LiF, MgF2 and their mixture) on microstructure and electrical properties of 0.68 Pb(Mg1/3Nb2/3)O3–0.32 PbTiO3 (PMNT) ceramic was investigated. The X-ray study has shown each sample to be a pseudo-cubic perovskite single phase. Microstructure analysis has shown the fluoride-doped PMNT ceramics exhibit a typical liquid phase sintering character, and the fracture of LiF containing PMNT ceramics is transgranular fracture. The dielectric constants of fluoride-doped PMNT ceramics are higher than that of pure PMNT ceramic. The LiF containing PMNT ceramics have more apparent diffusion phase transition (DPT) and frequency dispersion than pure and MgF2-doped PMNT ceramics. These results may be ascribed to structural disorder and compositional fluctuations in solid solution. The LiF containing PMNT ceramics have better piezoelectric properties than the other two samples. The values of d 33 and K p for LiF-doped PMNT ceramic arrive to 624 pC/N and 68%, respectively.
KeywordsPMNT Fluoride Microstructure Dielectric and piezoelectric properties
This work was financially supported by the Ministry of Science and Technology of China through 973-project under Grant No. 2002CB613307, and the Natural Science Fund of China under Grant No. 50472052, and Key Science and Technology Research Project from the Ministry of Education of China under Grant No. 03155.
- 1.L.E. Cross, S.J. Jang, R.E. Newnham, Ferroelectrics 23, 187 (1980)Google Scholar
- 5.J.M. Haussonne, G. Desgardin, Ceram. Trans. 32, 155 (1993)Google Scholar
- 7.L.H. Cao, X. Yao, Z. Xu, Rare Metal Mater. and Eng. 34(Suppl. 1), 791 (2005)Google Scholar
- 9.Y. Li, Z.K. Qin, Z.G. Zhou, Measurement of Piezoelectric and Ferroelectric Materials. (Science Press, Beijing, 1984), p. 206Google Scholar