The interpretation of dislocation contrast in x-ray topographs of GaAs _1-x P_x

Misfit accommodation in epitaxially grown GaAs1-xPx was examined by x-ray topography which shows crosshatch contrast and by transmission electron microscopy which reveals individual misfit dislocations. Of these misfit dislocations 80% are glissile 60°dislocations and the remainder are perfect edge dislocations. Contrast considerations show that the x-ray images are fully compatible with the actual dislocation structure although they cannot resolve the individual dislocations. © 1974 American Institute of Physics.