X‐ray diffraction, differential scanning calorimetry and evolved gas analysis of aged plutonium tetrafluoride (PuF4)

Synthesis and Morphological Control of UO2F2 Particulates

Uranium-based microspheres are of interest due to their potential applications as targets for medical isotopes production, as fuel for nuclear reactors, and as standardized materials for nuclear forensics. Here, for the first time, UO₂F₂ microspheres (1-2 μm) have been prepared from the reaction between UO₃ microspheres and AgHF₂ in an autoclave. In this preparation, a new fluorination method has been applied, and HF_(g)-produced in situ from the thermal decomposition of AgHF₂ and NH₄HF₂-was used as the fluorinating agent. The microspheres were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Diffraction results indicated that the reaction performed with AgHF₂ at 200 °C led to anhydrous UO₂F₂ microspheres, while at 150 °C, hydrated UO₂F₂ microspheres were obtained. Meanwhile, NH₄HF₂ led to the formation of contaminated products as driven by the formation of volatile species.