Direct observation by high resolution electron microscopy of coincidence sites in domain boundaries in ordered gold‐manganese alloys

In the course of a high resolution electron microscopic study of different gold‐manganese alloys, the inclined domain boundaries between different coaxial orientation variants are analysed in Au₄Mn and Au₅Mn₂. Assuming that continuous columns of manganese atoms, parallel with the beam direction, are imaged as bright dots, the complicated pattern of overlapping domains can be understood. The coincidence sites of columns of manganese atoms in both regions form a two dimensional structure which can be directly observed. The lattice is the same for all coaxial twins: the motif is different.