The chemical composition of a metal/ceramic interface on an atomic scale: The Cu/MgO {111} interface

Abstract

Keywords: Metal/ceramic interface, internal oxidation, Cu/MgO heterophase interface, high resolution electron microscopy, atom-probe field-ion microscopy.Abstract. The chemical composition profile across a Cu/MgO {lll}-type heterophase interface, produced by the internal oxidation of a Cu(Mg) single-phase alloy at 1173 K, is measured via atomprobe field-ion microscopy with a spatial resolution of 0.121 nm; this resolution is equal to the interplanar spacing of the {222) MgO planes. In particular, we demonstrate directly that the bonding across a Cu/MgO {lll}-type heterophase interface, along a <111> direction common to both the Cu matrix and an MgO precipitate, has the sequence CulOIMg... and not CulMglO... ; this result is achieved without any deconvolution of the experimental data. Before determining this chemical sequence, it was established, via high-resolution electron microscopy, that the morphology of an MgO precipitate in a Cu matrix is an octahedron faceted on {111} planes with a cube-on-cube relationship between a precipitate and the matrix; that is, {111}Cu//{222}MgO and < 110 >cu//< 110 >MgO.

In-situ TEM analysis of the reduction of nanometre-sized Mn3O4 precipitates in a metal matrix

“…TiO 2 ). In the starting condition the terminating {111} planes of Mn 3 O 4 at the interface are a polar planes of oxygen atoms only [41][42][43][44][45]. Upon sufficient reduction the terminating planes will be composed of Mn cations (or they have at least a much reduced oxygen occupancy) [41,45].…”

Influence of misfit and interfacial binding energy on the shape of the oxide precipitates in metals

“…MgO, MnO, CdO, NiO) as grown by internal oxidation in fcc metals are predominantly present in octahedrally shaped precipitates bounded by parallel {111} planes of both metal and oxide [19][20][21][22][24][25][26][27][28][29][30]. In the oxide {111} corresponds to a polar interface.…”

“…Further, the O-terminated {111} interface was more stable than the Mg-terminated one. The mismatch between these fcc metals and NaCl structured oxides is usually quite large and closely spaced misfit dislocations are generated [19][20][21][24][25][26][27][28][29][30]. Consequently, the influence of misfit on the energy of facets cannot be deduced because it will be largely similar for all possible types of facet and hence does not result in observable deviations from the shape according to the Wulff energy construction in the absence of misfit.…”

“…MgO, MnO, NiO, CdO) in an fcc metal matrix [19][20][21][22][23][24][25][26][27]. These systems are not interesting for studying the relative importance of misfit on the shape of oxide precipitates, since an isotropic mismatch between precipitate and matrix is present.…”

Solid Solutions of Hydrogen in Complex Materials

“…Due to the large H-solubility and the ease of measuring chemical potentials palladium alloys are used as model alloys again. For some metal/oxide interfaces high resolution electron microscopy and analytical field ion microscopy [93,94,95,96] revealed that most of the terminating layers are dense packed oxygen planes (cf. Fig.…”