Soft X-Ray Resonant Diffraction Study of Magnetic and Orbital Correlations
We have utilized resonant x-ray diffraction at the Mn LII/III edges in order to directly compare magnetic and orbital correlations in Pr0.6Ca0.4MnO . Comparing the widths of the magnetic and orbital diffraction peaks, we find that the magnetic correlation length exceeds that of the orbital order by nearly a factor of 2. Furthermore, we observe a large (~3 eV) spectral weight shift between the magnetic and orbital resonant line shapes, which cannot be explained within the classic Goodenough picture of a charge-ordered ground state. To explain the shift, we calculate the orbital and magnetic resonant diffraction line shapes based on a relaxed charge-ordered model.
in a Manganite Near Half Doping
K. J. Thomas, J. P. Hill, S. Grenier, Y-J. Kim, P. Abbamonte, L.Venema, A. Rusydi, Y. Tomioka, Y. Tokura,D. F. McMorrow, G. Sawatzky, and M. van Veenendaal (6.2004)
Phys. Rev. Lett. 92, 237204 (2004).
Polarized Resonant Inelastic X-ray Scattering in NaV2O5,
Resonant Inelastic X-ray Scattering has been increasingly used to study strongly correlated systems. Zhang et al. [Phys. Rev. Lett. 88, 077401 (2002)] used RIXS to study valence excitations in the ladder compound NaV2O5. We have shown the importance of including the core-hole potential and polarization effects in the interpretation of their experiments. We find that the feature, Zhang et al. ascribe to an excitation across the Hubbard gap is in fact not the lowest excitation state and should be ascribed to a local dd-transition.
M. van Veenendaal and A. J. Fedro (5.2004)
Phys Rev. Lett. 92, 219701 (2004)
Polarization dependence of x-ray emission spectroscopy
The polarization dependence of x-ray emission spectroscopy (XES) is studied by employing the angle dependence of incident and emitted x-ray. The Kramers-Heisenberg formula is used to describe the optical process. It is shown that the quantum mechanical interference effect is directly observable in magnetic circular dichroism spectra in a special geometrical configuration. It is also shown that by making use of the linearly polarized x-ray, information on the symmetry of ground states of materials can be directly determined from simple selection rules. Potential possibilities of x-ray spectroscopy with polarized X-rays are demonstrated.
H. Ogasawara, K. Fukui, and M. Matsubaru (11.2003)
J. El. Spec. 136, 161 (2004).