Temperature Resolved X‐ray Diffraction for the Investigation of the Phase Transitions of FOX‐7

Abstract The phase behavior of 1,1‐Diamino‐2,2‐dinitroethylene (FOX‐7) was investigated by means of temperature resolved X‐ray powder diffraction. Three phases were observed, and α‐ and β‐FOX‐7 were identified by X‐ray diffraction. The following transition scheme was found: Heating: α → β → γ at 113 °C (α→β) and 173 °C (β→γ) Cooling: α (+γ) ← γ between 50 and 75 °C The α/β‐transition is completely reversible, and the γ/α‐transition on cooling revealed to be incomplete. A fourth phase which is described in literature was not found.