Resonant x-ray scattering spectra from multipole ordering: Np M4,5 edges in Np O2
Abstract
We study resonant x-ray scattering (RXS) at Np M4,5 edges in the triple- k multipole ordering phase in NpO2 , on the basis of a localized electron model. We derive an expression for RXS amplitudes to characterize the spectra under the assumption that a rotational invariance (spherical symmetry) is preserved in the Hamiltonian describing the intermediate state of the scattering process. This assumption is justified by the fact that the energies of the crystal electric field and the intersite interaction are smaller than the energy of multiplet structures. This expression is found to be useful to calculate energy profiles taking account of the intra-Coulomb and spin-orbit interactions. Assuming the Γ8 -quartet ground state, we construct the triple- k ground state and analyze the RXS spectra. The energy profiles are calculated in good agreement with the experiment, providing a sound basis to previous phenomenological analyses.
- Publication:
-
Physical Review B
- Pub Date:
- November 2005
- DOI:
- 10.1103/PhysRevB.72.174421
- arXiv:
- arXiv:cond-mat/0506467
- Bibcode:
- 2005PhRvB..72q4421N
- Keywords:
-
- 78.70.Ck;
- 75.25.+z;
- 75.10.-b;
- 78.20.Bh;
- X-ray scattering;
- Spin arrangements in magnetically ordered materials;
- General theory and models of magnetic ordering;
- Theory models and numerical simulation;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 10 pages, 7 figures