The incommensurate structure of (Sr, Ca)₁₄Cu₂₄O₄₁: a study by electron diffraction and high-resolution microscopy

The modulated structure in (Sr, Ca)₁₄Cu₂₄O₄₁ has been studied using electron diffraction and high-resolution microscopy. The structure can be considered as consisting of two interpenetrating substructures. The first sheet-like substructure is shown to be hardly modulated while the second substructure, consisting of c-oriented chains, contains most of the modulation. High-resolution electron microscopy allows either separate imaging of the two substructures or identification of the misfit between them.