1305.0198 (J. Laverock et al.)

Electronic structure of the kagome staircase compounds Ni3V2O8 and
Co3V2O8    [PDF]

J. Laverock, B. Chen, A. R. H. Preston, K. E. Smith, N. R. Wilson, G. Balakrishnan, P. -A. Glans, J. -H. Guo

The electronic structure of the kagome staircase compounds, Ni3V2O8 and Co3V2O8, has been investigated using soft x-ray absorption, soft x-ray emission, and resonant inelastic x-ray scattering (RIXS). Comparison between the two compounds, and with first principles band structure calculations and crystal-field multiplet models, provide unique insight into the electronic structure of the two materials. Whereas the location of the narrow (Ni,Co) d bands is predicted to be close to EF, we experimentally find they lie deeper in the occupied O 2p and unoccupied V 3d manifolds, and determine their energy via measured charge-transfer excitations. Additionally, we find evidence for a dd excitation at 1.5 eV in Ni3V2O8, suggesting the V d states may be weakly occupied in this compound, contrary to Co3V2O8. Good agreement is found between the crystal-field dd excitations observed in the experiment and predicted by atomic multiplet theory.

View original: http://arxiv.org/abs/1305.0198