Systematic study of elastic, electronic, and magnetic properties of lanthanum cobaltite oxide

Abstract

The electronic structure, elastic constants, and magnetic properties of lanthanum cobaltite oxide La 4Co 3O 9 compound, which crystallizes in orthorhombic space group Pnma, are investigated theoretically for the first time using the full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory plus Hubbard correction term (DFT + U). The calculated equilibrium lattice constants and fractional atomic coordinates are in a good agreement with available experimental data. Our result for the formation energy and elastic constants confirms that the predicted La 4Co 3O 9 is mechanically stable. This compound is found to be ductile in nature in accordance with Pugh’s criteria. The anisotropy factors (A1) , (A2) , and (A3) of La 4Co 3O 9 material are also predicted through the elastic constants. The electronic band structures show metallic behavior; the conductivity is mostly governed by Co-3d and O-2p states. The total magnetic moments of the tetrahedral (CoO 4) and octahedral (CoO 6) environments are, respectively, 2.502 μB and 2.874 μB, which are consistent with the experimental measurements.