First-principle study of hydrogen stability within TiCo₃

Samir F. Matar (1)

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

Structural and electronic changes due to hydrogen uptake within TiCo₃ are examined ab initio within DFT using both pseudo-potential and all electron calculations. For the monohydride two starting hypotheses for H position, at cube center and cube-edge middle, were considered and analyzed: the system stabilizes with a cubic structure which undergoes a tetragonal distortion when H is at edge middle. Detailed analyses of the site projected density of states and of the electron count conclude to meaningful changes of the electronic structure when H is inserted, especially for the weakening of the chemical bonding in the tetragonally distorted lattice. The results could explain the brittleness characterizing the hydrided 1:3 alloy systems.

Mots clés: DFT; AuCu₃-type; LDA; VASP; ASW; Hydrides

Domaines: Matériaux

Samir F. Matar. First-principle study of hydrogen stability within TiCo₃. Solid State Sciences, 2009, 11 (4), pp.894-899. ⟨10.1016/j.solidstatesciences.2009.01.004⟩. ⟨hal-00377758⟩