Crystal Structure Evolution of UCl3 from Room Temperature to Melting

Uranium trichloride (UCl3) is actively researched to develop and improve applications ranging from molten salt reactors to actinide processing, including spent fuel reprocessing. Here, we report for the first time the crystal structure evolution between room temperature and melting point from in situ high-temperature neutron diffraction to quantify, for example, the thermal expansion of the hexagonal a and c lattice parameters. The results are compared with density functional theory calculations. The melting point of UCl3 is determined by differential scanning calorimetry to be 1108.2 +/- 0.2 K.

Automated summary

Uranium trichloride (UCl3) is actively researched for various applications, such as molten salt reactors and actinide processing. The crystal structure evolution of UCl3 from room temperature to its melting point was studied using high-temperature neutron diffraction, with the thermal expansion of lattice parameters quantified. The melting point of UCl3 was determined to be 1108.2 K by differential scanning calorimetry.