Mismatch and misalignment at interfaces between Ag and Mn3O4 studied with HRTEM

Internal oxidation of Ag-3at.%Mn resulted in Mn3O4 precipitates with a ''parallel'' topotaxy with the metal matrix and an octahedron shape due to {111} facets. Due to the tetragonality of Mn3O4, only a few planes and directions of Ag and Mn3O4 can be actual parallel. The precipitates exhibited a preference to align {111} planes parallel with the matrix for one pair of facets and then for another pair a tilt of 7.6 degrees occurs which is relieved by ledges in Ag. The dislocation structure at these parallel and tilted (111) interfaces, originating from a 1-dimensional mismatch and including phenomena such as stand-off and dissociation of dislocations, was scrutinized.