High Resolution Electron Microscopy of Cu/MgO and Pd/MgO Interfaces

Cu/ (11̄1) MgO and Pd/ (11̄1) MgO interfaces with a cube-on-cube relation are produced by internal oxidation technique. High resolution transmission electron microscopy has been applied to study the interface structure of Cu/ (11̄1) MgO and Pd/ (11̄1) MgO. In contrast to a previous work in which cases the core structure of interfacial dislocation in Cu/ (11̄1) MgO and Pd/ (11̄1) MgO interfaces can not be directly observed from the high resolution image, we have observed the localized interfacial dislocation in both Cu/(11̄1) MgO and Pd/ (11̄1) MgO interfaces from high resolution images. The atomic structure of these two metal/oxide interfaces are determined from through-focal series of high resolution images. The terminating lattice plane in the interface is the oxygen lattice plane for both Cu/ (11̄1) MgO and Pd/ (11̄1) MgO interfaces which are composed of the distorted structural units of Cu₂O and PdO, respectively. Junction dislocation resemble to that in the grain boundary facets related to the difference of the rigid body translations between two energetically equivalent {11̄1} facets in the Cu/ MgO and Pd/ MgO interfaces is observed. The Burgers vector of the junction dislocation is 1/6 〈112〉 and a stacking fault in the soft metal matrix accompanying with this junction dislocation is found.