The determination of the type of stacking faults in face centered cubic alloys by means of contrast effects in the electron microscope

A practical method is described for the determination of the nature of stacking faults in facecentred cubic structures. The method involves a comparison of the bright and dark field image of the fringe pattern associated with a stacking fault lying in an inclined plane. A complete analytical derivation of the principles of the method is given , and it is used to show that the stacking faults in a copper -15% gallium alloy are of the intrinsic type.