Surface sensitivity effects with local probe scanning Auger-scanning electron microscopy

Ultra-high-vacuum segregation studies on in-situ fractured Cu-Sb alloys were performed in terms of nanometer scale scanning Auger/Electron microscopy. S contamination leads to the formation Of Cu2S precipitates which, upon removal due to fracture, expose pits with morphology that depends on the precipitate size and shape. Local variations of S and Sb distributions inside the pits were correlated to local surface orientations as Atomic Force Microscopy analysis revealed.</p

Modification of metal/oxide interfaces by dissolution of Sb in oxide precipitates containing metal matrices

The influence of dissolution of a segregating element (Sb) in a metal matrix in which oxide precipitates are present on the precipitate morphology and the interface structure is studied using HRTEM. The influence on Mn3O4 precipitates in Ag is distinct: (i) the initial precipitates, sharply facetted by solely {111}, are changed into a globular shape with sometimes also short {220} and (002) facets, (ii) a partly reduction of Mn3O4 into MnO occurs for a part of the precipitates. Further Sb appeared to prevent Oswald ripening of the precipitates. The influence on MnO and MgO precipitates in Cu is more subtle: only a small but significant increase of the facet lengths of the {200} (and {220}) relative to the {111} occurs. The influence of Sb can be explained by a large decrease of the energy of steps at Ag/Mn3O4 interfaces and by a stronger tendency for segregation of Sb to {200} and {220} than to {111} facets of the Ag/Mn3O4, Cu/MnO and Cu/MgO interfaces.</p

Modification of metal/oxide interfaces by dissolution of Sb in oxide precipitates containing metal matrices

The influence of dissolution of a segregating element (Sb) in a metal matrix in which oxide precipitates are present on the precipitate morphology and the interface structure is studied using HRTEM. The influence on Mn3O4 precipitates in Ag is distinct: (i) the initial precipitates, sharply facetted by solely {111}, are changed into a globular shape with sometimes also short {220} and (002) facets, (ii) a partly reduction of Mn3O4 into MnO occurs for a part of the precipitates. Further Sb appeared to prevent Oswald ripening of the precipitates. The influence on MnO and MgO precipitates in Cu is more subtle: only a small but significant increase of the facet lengths of the {200} (and {220}) relative to the {111} occurs. The influence of Sb can be explained by a large decrease of the energy of steps at Ag/Mn3O4 interfaces and by a stronger tendency for segregation of Sb to {200} and {220} than to {111} facets of the Ag/Mn3O4, Cu/MnO and Cu/MgO interfaces