A high resolution study of ordering in Au₄Mn. II. The evolution of ordering in Au₄Mn

Ordering in the Au₄Mn system is studied by electron diffraction and high resolution dark field electron microscopy. On fast quenching the alloy from above the ordering temperature diffuse streaking is observed by electron diffraction; a transition state characterized by the occurrence of tetrahedral clusters is formed. Slight annealing reveals a diffraction pattern strongly resembling the Watanabe‐type structure. Dark field resolution microscopy reveals a two dimensional long period antiphase boundary structure consisting of islands of the DO₂₂ structure; the boundaries itself having an uncommon orientation. On further ordering the Ni₄Mo‐type structure gradually forms while the transition structure disappears.