Long-period antiphase boundary structures in the ordered alloy Au4Zn. I. One-dimensional long-period antiphase boundary structure

The one-dimensional long-period superstructure in Au4Zn is studied using both electron microscopy and electron diffraction. Direct lattice imaging of the periodic or pseudo periodic antiphase boundaries gives a straightforward interpretation for deviations from the generally accepted M = 2 periodicity of the antiphase boundaries. Spacing and orientation anomalies in the diffraction pattern are explained by changes in the periodicity of the fault planes and jogging of the antiphase boundaries. This model is confirmed by optical simulation.