Uranium disulfide has two allotropic forms: α-uranium disulfide, which is stable above the transition temperature (about 1350 °C) and metastable below it, and β-uranium disulfide which is stable below this temperature.[3] The tetragonal crystal structure of α-US2 is identical to α-USe2.[1]
Uranium disulfide can be synthesized by reduction of gaseous hydrogen sulfide with uranium metal powder at elevated temperatures.[4]
References
^ abNoel, H.; Le Marouille, J.Y. (1984). "Crystal structure and properties of the uranium chalcogenides α-US2 and α-USe2". Journal of Solid State Chemistry. 52 (3). Elsevier BV: 197–202. doi:10.1016/0022-4596(84)90001-x. ISSN0022-4596.