= Solution
Keep the matrix spots and add precipitate reflections at all integer $(h,k,0)$ with $0<h^2+k^2\leq8$. Even-even spots are fundamental; every other allowed position in this zone is a <superlattice reflection>. The added positions are $100,010,110,210,120$ and their symmetry-related signs. Each position actually denotes the corresponding signed index pair, not one radial ring. The precipitate grid spacing is $1/a_p$; the nearest fundamental separation is $2/a_p=0.4878\,\mathrm{\mathring A^{-1}}$. If matrix and precipitates are coherent and similarly oriented, their fundamental spots approximately coincide, with finite mismatch potentially giving splitting or broadening. The sketch assumes common orientation, small <strain>, appreciable sampled precipitate <volume> and predominantly single scattering; <electron diffraction> can have dynamical intensity effects.
Back to article page
