Abstract
Uranium mononitride (UN), sesquinitride (U2N3) and dinitride (UN2) were characterized by extended
X-Ray absorption fine structure spectroscopy. Analysis on UN indicate the presence of three uranium shells at distances of 3.46(3), 4.89(5) and 6.01(6) A ° and a nitrogen shell at a distance of 2.46(2) A ° . For U2N3, two absorbing uranium atoms at different crystallographic positions are
present in the structure. One of the uranium atoms is surrounded by nitrogen atoms at 2.28(2) A ° and by uranium atoms at 3.66(4) and 3.95(4) A ° . The second type of uranium atom is surrounded by nitrogen atoms at 2.33(2) and 2.64(3) A ° and by uranium atoms at 3.66(4), 3.95(4) and 5.31(5) A ° . Results on UN2 indicate two uranium shells at 3.71(4) and 5.32(5) A ° and two nitrogen shells at 2.28(2).