Journal: Advanced materials (Deerfield Beach, Fla.)

Article Title: Self-Oxidation Resistance of the Curved Surface of Achromatic Copper.

doi: 10.1002/adma.202210564

Figure Lengend Snippet: Figure 3. Surface structure analysis and origin of strong oxidation resistance in ACF. a) (left) Low-magnification ADF-STEM image of a top part of B-ACF, (middle) composite elemental maps of Cu (Cu K = 8.04 keV, green) and oxygen (O K = 0.525 keV, red) for B-ACF sample, and (right) ADF-STEM image of the interface region between Cu film and Al2O3 substrate. The white dashed square in the elemental map of middle panel denotes the imaging region. b,c) (left) ADF-STEM images of parts (denoted by L and R in (a)) of Cu nanograin depicting atomic steps on the surface and (right) superposition of atomic model with A–B–C planar stacking on each structure image. d) Projected atomic distance (PAD) maps for left (L), right (R), and top (T) parts of chosen Cu nanograin (denoted in a) and histogram of the measured PADs. e) DFT results. (left) Relative total energy profile of the O atom penetrating from outside into inside of biatomic step edge of a curved surface (violet open square □), compared with the biatomic step edge of a flat surface (black open square □); (right) Compression of the interlayer distances in (001) direction near the biatom step edge of curved surface of ACF. Blue spheres represent Cu atoms in bulk and dark blue spheres represent Cu atoms in the steps.

Article Snippet: In combination with STEM imaging, elemental mapping of the Cu films grown on Al2O3 (0001) substrates was performed in the same STEM imaging mode using an EDX spectrometer (JED-2300T, JEOL) with a dual-type silicon drift detector and a large effective solid angle (≈1.2 sr).

Techniques: Imaging