Ab initio investigations of the Ca₂IrO₄-type structure as a "post-K₂NiF₄": Case study of Na₂OsO₄

Samir F. Matar (1) , Gérard Demazeau (1) , Naïm Ouaïni (2)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 Faculté des Sciences et de Génie Informatique

Deriving the energy-volume equation of state for Na₂OsO₄ in its actual Ca₂IrO₄-type structure at high pressure and in hypothetic K₂NiF₄-type, leads to energy destabilization at a larger volume for the latter and to propose the former as a post-K₂NiF₄ through which a tuning of the magnetism and conductivity can be achieved: while the oxide system is magnetically silent in Ca₂IrO₄-type due to spin pairing (S = 0 for d² Os⁶⁺) with a semi-conducting behavior, a finite moment develops in the latter when spin polarization is accounted for (S = 1).

Mots clés: Ca2IrO4 and K2NiF4-type structures; DFT; PAW GGA; Chemical bonding; Magnetism

Domaines: Matériaux

Samir F. Matar, Gérard Demazeau, Naïm Ouaïni. Ab initio investigations of the Ca₂IrO₄-type structure as a "post-K₂NiF₄": Case study of Na₂OsO₄. Solid State Sciences, 2011, 13 (7), pp.1396-1400. ⟨10.1016/j.solidstatesciences.2011.04.011⟩. ⟨hal-00606549⟩