Low-Temperature Sintering of Apatite-Type Lanthanum Silicate with Fluoride Additives

Abstract:

Article Preview

Various fluorides (3 - 8 wt%) were added to a La9.33Si6O26 (LSO) powder synthesized by calcining the corresponding oxides mixture at 1100°C for 4 h. The addition of BaF2, AlF3 or Ba3Al2F12 caused an appreciable and substantial increase in bulk density after sintering at 1400º and 1450°C, respectively. These fluorides melt below 1400°C to form liquid phase which could assist the densification at low temperatures. Abnormal grain growth was observed for LSO samples with the addition of AlF3 and Ba3Al2F12, but it was effectively suppressed by stepwise sintering at 1400º and 1450°C. The BaF2 addition brought about the simultaneous promotion of densification and moderate grain growth, leading to the production of a densified LSO sample showing a conductivity of 1.5 x 10–2 Scm–1 at 800°C with an activation energy of 1.23 eV.

Info:

Periodical:

Edited by:

Pietro VINCENZINI and Jean-François BAUMARD

Pages:

235-240

Citation:

J. Takahashi et al., "Low-Temperature Sintering of Apatite-Type Lanthanum Silicate with Fluoride Additives", Advances in Science and Technology, Vol. 62, pp. 235-240, 2010

Online since:

October 2010

Export:

Price:

$38.00

[1] S. Nakayama and M. Sakamoto: J. Euro. Ceram. Soc. Vol. 18 (1998), p.1413.

[2] S. Nakayama, M. Sakamoto, M. Higuchi, K. Kodaira, M. Sato, S. Kakita, T. Suzuki and K, Itoh: J. Euro. Ceram. Soc. Vol. 19 (1999), p.507.

[3] J.R. Tolchard, M.S. Islam and P.R. Slater: J. Mater. Chem. Vol. 13 (2003), p. (1956).

[4] L. León-Reina, E.R. Losilla, M. Martinez-Lara, S. Bruque and M.A.G. Aranda: J. Mater. Chem. Vol. 14 (2004), p.1142.

DOI: https://doi.org/10.1039/b315257j

[5] R. Ali, M. Yashima, Y. Matsushita, H. Yoshioka, K. Ohoyama and F. Izumi: Chem. Mater. Vol. 20 (2008), p.5203.

[6] P.R. Slater, J.E.H. Sansom, and J.R. Tolchard: Chem. Record Vol. 4 (2004), p.373.

[7] J.E.H. Sansom, E. Kendrick, J.R. Tolchard, M.S. Islam and P.R. Slater: J. Solid State Electrochem. Vol. 10 (2006), p.562.

[8] H. Yoshioka and S. Tanase: Solid State Ioncs Vol. 176 (2005), p.2395.

[9] P.J. Panteix, I. Julien, D. Bernache-Assollant and P. Abélard: Mater. Chem. Phys. Vol. 95 (2006), p.313.

[10] A. Mineshige, T. Nakao, M. Kobune, T. Yazawa and H. Yoshioka: Solid State Ionics Vol. 179 (2008), p.1009.

DOI: https://doi.org/10.1016/j.ssi.2008.02.037

[11] M.N. Rahaman, in: Ceramic Processing and Sintering, 2nd ed., Marcel Dekker, Inc. NY (2003).

[12] P.R. Slater and J.E.H. Sansom: Solid State Phenomena Vol. 90-91(2003), p.195.

[13] A. Najib, J.E.H. Sansom, J.R. Tolchard, M.S. Islam and P.R. Slater: Dalton Trans. Vol. 19 (2001), p.3106.