Direct observation of charge order and an orbital glass state in multiferroic LuFe2O4

Geometrical frustration of the Fe ions in LuFe2O4 leads to intricate charge and magnetic order and a strong magnetoelectric coupling. Using resonant x-ray diffraction at the Fe K edge, the anomalous scattering factors of both Fe sites are deduced from the (h/3 k/3 l/2) reflections. The chemical shift between the two types of Fe ions equals 4.0(1) eV corresponding to full charge separation into Fe2+ and Fe3+. The polarization and azimuthal angle dependence of the superlattice reflections demonstrate the absence of differences in anisotropic scattering revealing random orientations of the Fe2+ orbitals characteristic of an orbital glass state. © 2009, American Physical Society

Keywords

Ferroelectric materials, Iron, Lutetium, Spin glass state, X-ray diffraction, Scattering

Citation

Mulders, A. M., Lawrence, S. M., Staub, U., García-Fernández, M., Scagnoli, V., Mazzoli, C., Pomjakushina, E., Conder, K., & Wang, W. D. (2009). Direct observation of charge order and an orbital glass state in multiferroic LuFe2O4. Physical Review Letters, 103(7), 4. doi:10.1103/PhysRevLett.103.077602