Journal of Materials Science

, Volume 4, Issue 2, pp 179–187 | Cite as

Dislocation reactions and cavitation studies in melt-grown sapphire

  • C. A. May
  • J. S. Shah


The veiled region in Czochralski sapphire has been examined for defects by optical micrography, scanning electron microscopy, electron microprobe analysis and X-ray topography. High optical scattering in the veiled region is found to be due to a large number of cavities. Some dislocation reactions have been observed in the X-ray topographs. High strain fields associated with cavities are also revealed by the topographs indicating that they contain entrapped gas at high pressure. This pressure is three orders of magnitude greater than that predicted from surface tension considerations.


Polymer Scanning Electron Microscopy Surface Tension High Pressure Cavitation 
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Copyright information

© Chapman and Hall 1969

Authors and Affiliations

  • C. A. May
    • 1
  • J. S. Shah
    • 1
  1. 1.H. H. Wills Physics LaboratoryThe UniversityBristolUK

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