Microstructure Characteristics in the BaTiO3-La2O3-Nb2O5 Ternary System


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A series of powders of (Ba1-xLa2x/3)(Ti1-xNb4x/5)O3 (0.05≤x≤0.3) have been synthesized by solid-state reaction route, and the effects of the dopants on the microstructure of BaTiO3 were investigated by XRD, SEM, HTEM and EDS in the BaTiO3-La2O3-Nb2O5 ternary system. It was found that the secondary titanium-rich phase occurred for x ≤ 0.1, while Ba3La3Ti5Nb5O30 yields as secondary phase for x ≥ 0.2. In the whole range of 0.05 ≤ x ≤ 0.3, the crystal structure of BaTiO3 solid solutions is cubic system. There are two substitution modes in the system: the substitution mode of La ions dissolved into Ba sites is significant for x ≤ 0.2, but the substitution mode of Nb ions dissolved into Ti sites is significant for x>0.2. TEM observation and EDS analysis revealed that the concentration gradient of Nb existed and La almost distributed homogeneously in a grain. Thus, the dielectric materials composed of La-Nb-codoped BT are not fitted to form the core-shell structure for the higher dopants.



Key Engineering Materials (Volumes 336-338)

Edited by:

Wei Pan and Jianghong Gong




Y. H. Wang et al., "Microstructure Characteristics in the BaTiO3-La2O3-Nb2O5 Ternary System", Key Engineering Materials, Vols. 336-338, pp. 177-180, 2007

Online since:

April 2007




[1] D. M. Finlay, C. S. Derek, M. S. Janet and R.W. Anthony: J. Am. Ceram. Soc. Vol. 81 (1998), pp. (1957).

[2] H. Chazono and H. Kisi: J. Am. Ceram. Soc. Vol. 82 (1999), p.2689.

[3] H. Chazono and M. Fujimoto: Jpn. J. Appl. Phys. Vol. 34 (1995), p.5353.

[4] D. Hennings and B. S. Schreinemacher: J. Euro. Ceram. Soc. Vol. 19 (1999), p.1061.

[5] F. Azough, R. Al-Saffar and R. Freer: J. Euro. Ceram. Soc. Vol. 18 (1998), p.151.

[6] H. M. Chan, M.R. Harmer and D.M. Smyth: J. Am. Ceram. Soc. Vol. 69 (1986), p.507.

[7] I. Teoreanu, E. Andronescu and A. Lanculescu: J. Interceram. Vol. 48 (1999), p.89.

[8] Y.L. Wang, L.T. Li, J.Q. Qi and Z. Gui: Ceramics International. Vol 28 (2002), p.657.

[9] C. J. Ting, C.J. Peng, H.Y. Lu and S.T. Wu: J. Am. Ceram. Soc. Vol. 73 (1990), p.329.

[10] D. Hennings and G. Rosenstein: J. Am. Ceram. Soc. Vol. 67 (1984), p.149.