X-RAY STUDIES OF SAPPHIRE CRYSTAL PERFECTION.

Abstract

The imperfection structure of A1203 single crystals was studied with the double crystal X-ray spectrometer. Preliminary rocking curve measurements on the basal planes of several sapphire and crystals indicated a dependence of peak multiplicity on rocking axis orientation. The results could be interpreted in terms of an ordered stacking of line dislocations having the <1120> Burgers vector. A pair of fully oriented 0 and 90 degree Verneuil crystals were examined by light microscopy, Laue back reflection photography and diffraction techniques, revealing major differences in imperfection structure between the two crystals. Detailed rocking curve surveys of the principal planes of the 90 degree crystal were made and dislocation densities calculated from the measured half-breadths in terms of proposed dislocation models. Good agreement is found between the calculated dislocation densities and those determined by etch pit counting. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 21, 1964
Accession Number
AD0601336

Entities

People

  • Christina Jansen
  • Harold Bernstein

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Agreements
  • Crystals
  • Diffraction
  • Dislocations
  • Measurement
  • Microscopy
  • Orientation (Direction)
  • Photographic Equipment
  • Photographic Materials
  • Photographic Recording Media
  • Photography
  • Reflection
  • Sapphire
  • Single Crystals
  • Spectrometers
  • X Rays

Readers

  • Materials Science and Engineering.