Observations par microscopie electronique de fautes ordonnees dans l'oxyde ReO2 monoclinique liees a la transformation structurale Re2O5 → ReO2

The formation of monoclinic ReO₂ from Re₂O₅ disproportion is studied by means of transmission electron microscopy and diffraction. The habit of single crystals of monoclinic oxide can be characterized as polygonal plates compatible with the space group $\text{P}\text{2}{}_1\text{c}$. A possible structural mechanism is described, involving the formation of cation vacancies and their regular arrangement, according to planar ordered faults observed on patterns.