DFT study of electronic and magnetic structure of perovskite and post-perovskite CaRhO₃

Samir F. Matar (1) , Gérard Demazeau (1) , Alain Largeteau (1)

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

Within density functional theory the equations of state for perovskite (PV) and post-perovskite (PPV) forms of CaRhO₃ are obtained with equilibrium values of volume in agreement with experiment. Energy magnitudes point to a stabilization of PPV versus PV. This is interpreted by analyses of the charge density and the chemical bonding plots, showing that the Rh–O interactions within two oxygen sublattices are selectively differentiated and reinforced for one of the two oxygen sublattices within PPV variety with respect to PV one. Investigation of the magnetic properties shows no magnetic order and a metallic character for PV while ferromagnetism occurs in PPV with a tendency to insulating behavior. This long range order is favored by direct t_2g–t_2g interactions through edge sharing octahedra in PPV CaRhO₃, stronger than indirect t_2g–p_π–t_2g ones in PV variety.

Mots clés: Perovskite; Post-perovskite; 4D-oxides; Chemical bonding; DFT; GGA; Magnetic interactions

Domaines: Matériaux

Samir F. Matar, Gérard Demazeau, Alain Largeteau. DFT study of electronic and magnetic structure of perovskite and post-perovskite CaRhO₃. Solid State Sciences, 2010, 12 (3), pp.373-378. ⟨10.1016/j.solidstatesciences.2009.11.017⟩. ⟨hal-00466759⟩