Effect of Al[sub 2]O[sub 3] and Bi[sub 2]O[sub 3] on the formation mechanism of Sn-doped Ba[sub 2]Ti[sub 9]O[sub 20]

Journal Article · Fri Apr 01 00:00:00 EST 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb07267.x· OSTI ID:7303223

Yu, J ^[1]; Zhao, H; Wang, J; Xia, F ^[2]

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1. Academia Sinica, Shenyang (China). Inst. of Corrosion and Protection of Metals
2. Academia Sinica, Shenyang (China). Inst. of Metal Research

High-performance Ba[sub 2]Ti[sub 9]O[sub 20] ceramics are attracting great attention, but their formation mechanism still is somewhat unclear. The present investigation shows that the formation of Ba[sub 2]Ti[sub 9]O[sub 20] can be promoted strikingly by the participation of Bi[sub 2]O[sub 3] and Al[sub 2]O[sub 3]. The effect of Bi[sub 2]O[sub 3] on the formation of Ba[sub 2]Ti[sub 9]O[sub 20] is attributed to the fact that migration of the involved reactants is accelerated by liquid which forms from the melting of Bi[sub 2]O[sub 3] above 830 C. This migration, however, is not the only rate-limiting factor. A high potential-energy barrier, resulting from stress that arises along the crystal-structured layers, also heavily restricts the formation of Ba[sub 2]Ti[sub 9]O[sub 20]. The participation of Al[sub 2]O[sub 3], on the other hand, can reduce the height of this potential-energy barrier and effectively improve the kinetics of the formation of Ba[sub 2]Ti[sub 9]O[sub 20] by causing the formation of BaAl[sub 2]Ti[sub 6]O[sub 16] crystals; these crystals intergrow with Ba[sub 2]Ti[sub 9]O[sub 20] crystals and result in decreased stress.

• OSTI ID: 7303223
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 77:4; ISSN 0002-7820
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
BARIUM OXIDES
FABRICATION
TITANIUM OXIDES
ALUMINIUM OXIDES
BISMUTH OXIDES
CALCINATION
CRYSTAL GROWTH
DOPED MATERIALS
EXPERIMENTAL DATA
MICROSTRUCTURE
POTENTIALS
TIN OXIDES
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
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THERMOCHEMICAL PROCESSES
TIN COMPOUNDS
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360201* - Ceramics
Cermets
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