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

Abstract

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+. Polarization and azimuthal angle dependence of the superlattice reflections demonstrates the absence of anisotropic scattering revealing random orientations of the Fe2+ orbitals characteristic of an orbital glass state.

v2: refined analysis, added supplement, PRL, accepted for publication

References in corpus (7)

• Multiferroics: different ways to combine magnetism and ferroelectricity
• Charge Order and the Origin of Giant Magnetocapacitance in LuFe2O4
• Charge order in LuFe2O4: antiferroelectric ground state and coupling to magnetism
• Resonant X-ray diffraction studies on the charge ordering in magnetite
• Charge-stripe order in the electronic ferroelectric LuFe2O4
• Manipulating the magnetic structure by electric fields in multiferroic ErMn2O5
• Doubly degenerate orbital system in honeycomb lattice: implication of orbital state in layered iron oxide

Cited by in corpus (12)

• Charge order in LuFe2O4: an unlikely route to ferroelectricity
• Electronic Ferroelectricity and Frustration
• Competing Ferri- and Antiferromagnetic Phases in Geometrically Frustrated LuFe2O4
• Ferroelectricity from iron valence ordering in rare earth ferrites?
• RASOR: An advanced instrument for soft x-ray reflectivity and diffraction
• Ferroelectric charge order stabilized by antiferromagnetism in multiferroic LuFe2O4
• Quantum fluctuation and geometrical frustration effects on electric polarization
• Stoichiometric YFe2O4-δ single crystals grown by the optical floating zone method
• Disentangling charge and structural contributions during coherent atomic motions studied by ultrafast resonant x-ray diffraction
• Magnetic excitation spectrum of LuFe2O4 measured with inelastic neutron scattering
• Quantum Dielectric Fluctuation in an Electronic Ferroelectricity studied by Variational Monte-Carlo Method
• A hybrid-exchange density-functional theory study of the electronic structure of ${\mathrm{MnV}}_2{\mathrm{O}}_4$: Exotic orbital ordering in the cubic structure