Abstract

The authors report on the spin polarized first principle investigations of a La_0.25Sm_0.75O_1.5 structure under the framework of Hubbard potential correction (LDA+U correction) for the potential between the localized electrons in the f- and d-orbital. The lattice parameters of the structure were extracted from Rietveld refinement of the X-ray diffraction pattern which revealed that the structure was monoclinic with C 12/m1 space group symmetry. The information about the structure’s symmetry allowed us to construct the random supercell, Sm₉La₃O₁₈, for the density functional first principle calculation. The Sm₉La₃O₁₈ has been generated with software for efficient stochastic generation of special quasi random structures. The Calculated Density of States (DOS) with LDA+U correction showed that the structure was non-metallic in contrast to the calculation without LDA+U correction which gave rise to a metallic structure. Similar LDA+U calculation on Sm6O9 has also revealed non-metallic structure in an agreement with the experiment on monoclinicSm₂O₃. The distribution of the DOS among the spin-up and spin-down electrons in the f and d orbitals suggest that the variation in the structure composition (percentage of Sm and La) and doping with another elements may give rise to an interesting controllability in the structure magnetization.

Keywords:Density functional calculation; Spin polarized first principle; LDA+U correction; Rare earth elements