Drastic changes in the electronic and magnetic structures of hydrogenated U2Ti intermetallic from first principles

Samir F. Matar (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Based on DFT calculations, hydrogen insertion in U2Ti intermetallic with AlB2-type structure leading to U2TiH3 with sites identified from energy discrimination between different hypotheses is found to decrease the cohesive energy through weakening of the Ti-U bonds, to expand the lattice along c hexagonal axis due to strong U-U in-plane bonding and to induce iono-covalent character with H−0.65. The anisotropic volume expansion involves a strong localization of out-of-plane uranium fz3-3zr2 orbitals leading to developing a magnetic moment on uranium in a predicted ferromagnetic ground state, opposite to non-magnetic intermetallic.

Mots clés: Intermetallic; Uranium; Magnetism; Bonding; Interstitial content; DFT; Electronic structure calculation

Domaines: Matériaux

Samir F. Matar. Drastic changes in the electronic and magnetic structures of hydrogenated U2Ti intermetallic from first principles. Journal of Magnetism and Magnetic Materials, 2014, 358-359, pp.70-75. ⟨10.1016/j.jmmm.2014.01.003⟩. ⟨hal-00956569⟩