Structural characterization of YV4O8: simultaneous analysis of coexisting polytypes and simulation of diffuse scattering for a stacking disorder model

The structure of a crystal of newly synthesized YV4O8 was refined on the assumption that two polytypes and their respective twin forms intergrow. The model was expressed as a commensurate composite crystal with two types of subsystem: one is a V4O8 framework with rather large tunnels and the other consists of Y ions. In the tunnels, Y ions and vacancies are located at every second site in an ordered manner that is characteristic of each polytype. Refinement was performed using a high‐dimensional formalism and all reflections from all domains. Diffuse streaks observed in the X‐ray and electron diffraction patterns were simulated using the matrix method that has been used for one‐dimensional disorder such as stacking faults. The unusual diffraction phenomena that occur in a crystal of YV4O8 are explained as arising from a multiple‐domain structure of coexisting polytypes.