162,080 research outputs found

    Insulating state and the importance of the spin-orbit coupling in Ca3_3CoRhO6_6

    Full text link
    We have carried out a comparative theoretical study of the electronic structure of the novel one-dimensional Ca3_3CoRhO6_6 and Ca3_3FeRhO6_6 systems. The insulating antiferromagnetic state for the Ca3_3FeRhO6_6 can be well explained by band structure calculations with the closed shell high-spin d5d^5 (Fe3+^{3+}) and low-spin t2g6t_{2g}^{6} (Rh3+^{3+}) configurations. We found for the Ca3_3CoRhO6_6 that the Co has a strong tendency to be d7d^7 (Co2+^{2+}) rather than d6d^6 (Co3+^{3+}), and that there is an orbital degeneracy in the local Co electronic structure. We argue that it is the spin-orbit coupling which will lift this degeneracy thereby enabling local spin density approximation + Hubbard U (LSDA+U) band structure calculations to generate the band gap. We predict that the orbital contribution to the magnetic moment in Ca3_3CoRhO6_6 is substantial, i.e. significantly larger than 1 ΞΌB\mu_B per formula unit. Moreover, we propose a model for the contrasting intra-chain magnetism in both materials.Comment: 7 pages, 4 figures, and 1 tabl
    • …
    corecore