GROWTH OF DISLOCATION-FREE GALLIUM CRYSTALS.
Abstract
Single crystals of gallium were grown with large portions free of dislocations detectable by anomalous transmission of x-rays. The crystals are grown by an unconstrained solidification technique. The very small supersaturation of vacancies in gallium at room temperature precludes the possibility of vacancy condensation and disc collapse as a mechanism of dislocation formation. Therefore, the absence of dislocations can be explained by the careful growth procedure that minimizes the sources of dislocations usually present during crystal growth. Networks of dislocations can be generated by scratching the surface of the crystal. It is found that the image of a dislocation network at the exit x-ray surface is well resolved while the same network at the entrance x-ray surface produces a completely unresolved image. This effect is attributed to the 'x-ray fan' or x-ray energy spread in the crystal perpendicular to the diffracting planes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1965
- Accession Number
- AD0616258
Entities
People
- C. Elbaum
- S. H. Mcfarlane Iii
Organizations
- Brown University