Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-06-16T11:05:42.454Z Has data issue: false hasContentIssue false

Characterization and control of phase segregation in the fine particles of BaTiO3 and SrTiO3 synthesized by the spray pyrolysis method

Published online by Cambridge University Press:  31 January 2011

K. Nonaka
Affiliation:
Department of Inorganic Materials, Faculty of Engineering, Tokyo Institute of Technology, 2–12–1 O-okayama, Meguro-ku, Tokyo 152, Japan
S. Hayashi
Affiliation:
Department of Inorganic Materials, Faculty of Engineering, Tokyo Institute of Technology, 2–12–1 O-okayama, Meguro-ku, Tokyo 152, Japan
K. Okada
Affiliation:
Department of Inorganic Materials, Faculty of Engineering, Tokyo Institute of Technology, 2–12–1 O-okayama, Meguro-ku, Tokyo 152, Japan
N. Otsuka
Affiliation:
Department of Inorganic Materials, Faculty of Engineering, Tokyo Institute of Technology, 2–12–1 O-okayama, Meguro-ku, Tokyo 152, Japan
T. Yano
Affiliation:
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2–12–1 O-okayama, Meguro-ku, Tokyo 152, Japan
Get access

Abstract

Fine particles of BaTiO3 and SrTiO3 have been synthesized by the spray pyrolysis technique, and the chemical homogeneity of their particles was analyzed by x-ray diffraction (XRD) and analytical electron microscopy (AEM). The stock solutions were prepared by dissolving Ti(OC3H7)4 and Ba(NO3)2 or Sr(NO3)2 in diluted nitric acid solution. They were atomized into a reaction chamber held at 1000 °C through a two-fluids atomizer with N2 gas. Mostly hollow spherical particles 3 μm in diameter were obtained, composed of very fine grains of 40 nm. As-prepared powders were crystallized to BaTiO3 or SrTiO3 with a small amount of by-product such as Ba2TiO4, Sr2TiO4, and TiO2. The AEM study revealed that the bulk composition of each particle was chemically homogeneous, but a local chemical composition segregation was observed within each particle. This chemical inhomogeneity was considered to be caused by the difference in the precipitating speed of each component from the precursor salts; that is, the precipitation of Ti4+ ion as TiO2 · xH2O was faster than those of Ba2+ and Sr2+ ions. To control this segregation, (a) replacing a part of the solvent of stock solutions with methanol or ethanol, (b) adding H2O2 to the solutions, and (c) increasing the concentration of the solution, are found to be effective. The reasons for these effects are discussed.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Sproson, D. W. and Messing, G. L., in Advances in Ceramics vol. 21: Ceramic Powder Science, edited by Messing, G. L., Mazdiyasni, K. S., McCauley, J. W., and Haber, R. A. (The American Ceramics Society, Westerville, OH, 1987), p. 99.Google Scholar
2.Takigawa, K., Nonaka, K., Okada, K., and Otsuka, N., Br. Ceram. Trans. J. 89, 742 (1990).Google Scholar
3.Hayashi, S., Otsuka, N., Akiyama, K., Okada, K., and Yano, T., J. Ceram. Soc. Jpn. 97, 82 (1989).Google Scholar
4.Nonaka, K., Onishi, Y., Hayashi, S., Okada, K., Yano, Y., Uematsu, K., Saito, K., and Otsuka, N., ibid. 98, 794 (1990).Google Scholar
5.Sakurai, O., Mizutani, N., and Kato, M., ibid. 94, 813 (1986).Google Scholar
6.Sakurai, O., Mizutani, N., and Kato, M., ibid. 96, 639 (1988).Google Scholar
7.Sakura, O., Miyauchi, M., Mizutani, N., and Kato, M., ibid. 97, 407 (1989).Google Scholar
8.Nukiyama, S. and Tanasawa, Y., Trans. Soc. Mech. Engrs. (Japan) 4, No. 14, 86, No. 15, 138 (1938); 5, No. 18, 63, 68 (1939); 6, No. 22, II-7, No. 23, II-8 (1940).Google Scholar
9.Hall, W. H., Proc. Phys. Soc. 62, 741 (1949).CrossRefGoogle Scholar
10.Cliff, G. and Lorimer, G. W., J. Microsc. 103 203 (1975).CrossRefGoogle Scholar
11.Nonaka, K., Hayashi, S., Okada, K., Otsuka, N., and Yano, T., The Ceramic Society of Japan, Proceedings of 1990 Annual Meeting, 591 (1990).Google Scholar
12.Kubo, K. and Zinriki, K., Kogyokagaku-zasshi, 56, 335 (1953).CrossRefGoogle Scholar
13.Binran, Kagaku, I, edited by the Chemical Society of Japan, (Maruzen, Tokyo, 1966), p. 92.Google Scholar
14.Stern, K. H., J. Phys. Chem. Ref. Data 1, 747 (1972).Google Scholar
15.McNamara, , Can. J. Ceram. Soc. 34, 103 (1965).Google Scholar
16. Rep. Nat. Inst. Res. Inorg. Mater. 49, 4 (1986).Google Scholar
17.Kakegawa, K., Arai, K., Sasaki, Y., and Tomizawa, T., J. Am. Ceram. Soc. 71, C-49 (1988).Google Scholar
18.Babko, and Valkova, , C.A. 42 (1948) 44836.Google Scholar
19.Mori, M., Shibata, M., Kyuno, E., and Ito, S., Bull. Chem. Soc. Jpn. 29, 904 (1956).CrossRefGoogle Scholar
20.Yano, T., Nonaka, K., Saito, K., and Otsuka, N., J. Ceram. Soc. Jpn. 95, 111 (1987).Google Scholar
21.Nonaka, K., Yano, T., and Otsuka, N., J. Ceram. Soc. Jpn. 97, 941 (1989).CrossRefGoogle Scholar