First-principles comprehensive study of electronic and mechanical properties of novel uranium hydrides at different pressures

Publication date: Available online 13 February 2020Source: Progress in Natural Science: Materials InternationalAuthor(s): Min Liu, Yongpeng Shi, Mingfeng Liu, Dianzhong Li, Wenlin Mo, Tao Fa, Bin Bai, Xiaolin Wang, Xingqiu ChenAbstractThe systematic investigation on the U–H binary system up to 300 GPa has been performed by means of first-principles calculations in combination with the variable-composition evolutionary algorithm. Twenty uranium hydrides, including UHx (x = 1, 2, 3, 4, 5, 6, 7, 8, 9, 17), U2Hy (y = 3, 5, 7, 13, 15, 17), U3H8, U3H10, U4H5 and U4H9 have been found under different pressures. Besides thirteen compounds that are in nice agreement with previously reported structural search, new uranium hydrides in terms of the derived convex hull of the formation enthalpies have also been found in the present investigation. These seven novel compounds including Cmcm-UH3, Fmmm-UH4, R3‾m-U2H7, Pm–U2H15, Cm–U3H8, C2–U4H9 and C2/m-U4H5, are found to be dynamically and thermodynamically stable, and their stable pressure range has been determined. At last, the electronic and mechanical properties of these seven novel structures have further been calculated.Graphical abstract

Source: Progress in Natural Science: Materials International - February 15, 2020 Category: Materials Science Source Type: research