Study on the electronic structure of α-U2N3 by XPS and first principles

•XPS spectra of α-U2N3 indicates that α-U2N3 has some metallic bonding character.•First principles calculation was the first time carried out on α-U2N3.•Experimental and theoretical results show the U 5f electrons of α-U2N3 are in localized state.•Compared with UN, the covalent property of α-U2N3 is more evident.

Film samples of α-U2N3 were prepared. The stoichiometry and crystal structure of the samples were identified to be α-U2N3 by AES and XRD separately. U 4f peaks in XPS spectra are obvious asymmetry, indicating that α-U2N3 has some metallic bonding character. The U 5f electrons are in localized state, which produces a strong and sharp peak near the Fermi level. The theoretical results from first principles calculations are in good agreement with the XPS data. Compared with UN, the valence charge of U atoms in α-U2N3 is higher, and the covalent property between U–N atoms is more evident. However, in XPS spectra no distinct shift of N 1s peaks is observed between the two nitrides.