Insular crystals in undoped GaAs single crystals: A probable source of dislocation

Abstract
We have observed particles of size ∼1000 Å in semi-insulating single crystal GaAs. Using diffraction, dark-field imaging and x-ray microanalysis in the electron microscope, we have identified one such particle as consisting of a polycrystalline GaAs insular. We propose that such insulars act as sources for dislocations.