Determination of the Σ 21 [211] orientational relationship in a MgO/Cu composite

The microstructure of an internally oxidized CuMg alloy has been examined by means of high-resolution transmission electron microscopy. A new orientational relationship, Σ 21 [211], has been determined by selected-area electron diffraction. The dislocation network for such an orientational relationship, calculated using the near coincident site lattice theory, is a parallel array of edge dislocations with Burgers vectors of the type 1/21[1 0 2 1̄], 1/21[1 4̄ 2], and 1/21[4̄ 5̄ 8̄].