Comparing Five and Lower-Dimensional Grain Boundary Character and Energy Distributions in Copper: Experiment and Molecular Statics Simulation

Abstract

The misorientation of 515 grain boundaries has been determined using electron back scatter diffraction data from an 18 μm thick copper foil with columnar grain structure and a preferential {110} surface orientation. The energy of the grain boundaries was determined from the dihedral angles in the vicinity of grain boundary thermal grooves. The experimental grain boundary energy vs. misorientation angle shows deep minima for the low angle grain boundaries and small minima corresponding to the Σ3 and Σ9 grain boundaries. Only a small fraction of the coincidence site lattice grain boundaries demonstrate an increased occurrence frequency (compared to a random orientation distribution) and low energy. In parallel, the grain boundary energy for a subset of 400 symmetrical tilt grain boundaries was calculated using molecular statics simulations. There is a good agreement between the experiment and molecular statics modeling.

The Role of Grain Boundary Sites for the Oxidation of Copper Catalysts during the CO Oxidation Reaction

“…Besides these two facets, a stepped Cu (111) surface was simulated, which was built by removing one row of the Cu (111) slab model to expose the {111} microfacet, keeping the number of frozen layers intact. To further gain insights about the role of grain boundaries, the surface of Cu’s coherent twin boundary, experimentally determined to be one of the most abundant grain boundaries in Cu’s surfaces, − was also studied. This boundary, defined under the coincidence site lattice (CSL) theory, is specified by a multiplicity index, Σ = 3, the {111} grain boundary plane and the ⟨111⟩ rotation axis.…”