Characterization of stacking faults with the field-ion microscope

A new sign convention for fault vectors and Burgers vectors of partial dislocations is introduced. Using this convention, methods for distinguishing between intrinsic and extrinsic faults in field-ion micrographs arc developed. In general the type of the fault is deduced from the relative displacements of the atoms in the two sides of the plane of the fault; this information can be obtained from the micrographs. Different methods are used, depending on whether or not the fault ends in an imaged pole. The characterization of {111} faults in f.c.c. metals is considered in detail.