Theoretical study of the electronic states of hollandite vanadate K${}_2$V${}_8$O${}_{16}$

Abstract

We consider electronic properties of hollandite vanadate K${}_2$V${}_8$O${}_{16}$, a one-dimensional zigzag-chain system of $t_{2g}$ orbitals in a mixed valent state. We first calculate the Madelung energy and obtain the relative stability of several charge-ordering patterns to determine the most stable one that is consistent with the observed superlattice structure. We then develop the strong-coupling perturbation theory to derive the effective spin-orbit Hamiltonian, starting from the triply-degenerate $t_{2g}$ orbitals in the VO${}_6$ octahedral structure. We apply an exact-diagonalization technique on small clusters of this Hamiltonian and obtain the orbital-ordering pattern and spin structures in the ground state. We thereby discuss the electronic and magnetic properties of K${}_2$V${}_8$O${}_{16}$ including predictions on the outcome of future experimental studies.

arXiv comment7 pages, 8 figures

References in corpus (2)

• Anisotropy of Mott-Hubbard gap transitions due to spin and orbital ordering in LaVO3 and YVO3
• Charge and Orbital Ordering in the Triangular-Lattice t_{2g}-Orbital System in One Dimension: A Possible Ground State of Bi_xV_8O_{16}

Cited by in corpus (2)

• K${}_2$Cr${}_8$O${}_{16}$ predicted as a half-metallic ferromagnet: Scenario for a metal-insulator transition
• Structural instability and the Mott-Peierls transition in a half-metallic hollandite : K${}_2$Cr${}_8$O${}_{16}$