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Journal of Materials Science

, Volume 30, Issue 11, pp 2981–2988 | Cite as

Crystal growth of thin-plate β-alumina by liquid transport

  • M. Ushio
Papers

Abstract

Single crystals of β-alumina (Na20.11Al2O3) were grown by liquid transportat 1030–1150 °C and for durations of 4–140 h, using an Na3AlF6 solvent and α- or β-alumina as the nutrient. The maximum size of β-alumina crystal grown using a small platinum crucible was 1.1 cm in length and 0.6 mm in thickness. On the other hand, a single crystal 1.8 m long and 0.7 mm thick was grown using a large crucible. These grown single crystals were hexagonal, thin platelike, and very transparent. Screw dislocation-like patterns were observed on the surfaces of grown β-alumina single crystals; each pattern showed a right-handed rotation. Small crystals on a matrix crystal grew spirally about the c-axis and formed a new, flat surface on the matrix crystal, evidently an intrusive twin. The angle between the two inclined crystals was ∼ 2.9–2.8 °. The twin face seemed to be w(14, 14, 3). The growth rates of β-alumina single crystals treated for less than 12 h using large and small crucibles were 3.3 × 10−1 and 4.0 × 10−1 mm h−1, respectively. For treatment ranging from 12 to 40 h growth rates were 1.1 × 10−1 and 1.5 × 10−1 mm h−1 for the large and small crucible, respectively; rates for 40–100 h treatment were 0.3 × 10−1 mm h −1 for both crucibles. The grown β-alumina single crystals had fairly good crystallinity. The growth mechanism of the β-alumina single crystal can be estimated from transport through liquid film in the crucible, i.e. a creeping phenomenon.

Keywords

Al2O3 Hexagonal Crystal Growth Flat Surface Liquid Film 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • M. Ushio
    • 1
  1. 1.Department of Applied Chemistry, Faculty of EngineeringGunma UniversityKiryu-shiJapan

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