Abstract
Electron microscopy has been used to study the structure of Cu/MgO and Pd/MgO interfaces formed by internal oxidation of Cu-1wt%Mg and Pd-1wt%Mg alloys. For the Cu/MgO system, the MgO particles exhibit a cube-on-cube orientation relationship with the Cu matrix and are octahedrally shaped with principal facets parallel to {111} lattice planes of MgO and Cu. For the Pd/MgO system, however, both tetradecahedron and plate-like MgO precipitates are observed. The tetradecahedrally shaped particles also exhibit a cube-on-cube orientation relationship with the Pd with principal facets parallel to {111} and {100} lattice planes. The plate-like MgO precipitates have two of their {111} surfaces parallel to the {111} surface of Pd and exhibit a twin orientation relationship with respect to the Pd matrix. All interfaces are partially coherent. The localized misfit dislocations at Pd/MgO{111} and {100} interfaces are visible by weak-beam imaging. For both Cu/MgO and Pd/MgO interfaces, the periodic strain contrast caused by misfit dislocations are seen in HREM micrographs. Image simulations have been performed to confirm the presence of misfit dislocations.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call