Ferromagnetism and antiferromagnetism coexistence in Sr1-xLaxRuO3 induced by La-doping.

Recently, a spin-glass state appeared experimentally along with suppression of ferromagnetism in polycrystalline La-doped Sr 1-x La x RuO 3 . Here, we investigated the structural, magnetic and electronic properties of Sr 1-x La x RuO 3 (x = 0, 0.125, 0.25, 0.5, 1) based on generalized gradient approximation plus U (GGA + U) by first-principles calculations. The entire series of Sr 1-x La x RuO 3 (x = 0, 0.125, 0.25, 0.5, 1) stabilize in the orthorhombic perovskite structure. The spin-polarized calculations give a ferromagnetic half-metal ground state at 0 ≤ x ≤ 0.25, coexistence of a ferromagnetic half-metal state and antiferromagnetic insulating state at x = 0.5 and an antiferromagnetic metal state at x = 1, in good agreement with experimental results. La substitution for Sr decreases Ru O Ru bond angles, resulting in stronger GdFeO 3 distortion. The stronger GdFeO 3 distortion reduces density of states at the Fermi level, with broadening of Van-hove singularity near the Fermi level. Therefore, suppression of magnetism in Sr 1-x La x RuO 3 becomes stronger with increasing x. La-doping weakens a Stoner mechanism for ferromagnetism in SrRuO 3 . These theoretical results interpret well experiments. [ABSTRACT FROM AUTHOR]