Browsing by Author "Colson, D"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Electric control of spin wave modes at room temperature in BiFeO3
    (Australian Institute of Physics, 2012-02-01) Rovillain, P; de Sousa, R; Gallais, Y; Sacuto, A; Measson, MA; Colson, D; Forget, A; Bibes, M; Barthélémy, A; Cazayous, M
    Multiferroic materials present the rare case to exhibit simultaneously magnetic and ferroelectric orders in interaction. This interaction corresponds to the magnetoelectric coupling. Thereby, magnetoelectric materials can potentially be used to control spins by an external electric field. This feature seems promising in spintronics and in magnonics that use magnetic excitations (spin wave) for information processing. In BiFeO3, a room-temperature magnetoelectric material, the interaction between the ferroelectric and magnetic orders offers the opportunity to control spins with an electric field. We have detected by Raman scattering two species of spin propagation modes (magnon) in BiFeO3 single crystal: in-plane (phi mode) and modes out of the cycloidal plane (psi mode) [1,2]. The frequencies of these modes have been successfully compared to the results of a Ginzburg-Landau mode [3]. Our result shows that the magnon modes might be interpreted as electromagnon. In order to characterize the magnetoelectric coupling, an external electric field has been applied. We show that in BiFeO3, the spin-wave frequency can be tuned electrically by over 30%, in a non-volatile way and with virtually no power dissipation [4]. These results showed that BiFeO3 is a very promising material for the generation and the control of spin waves in the future magnonic devices.
  • No Thumbnail Available
    Item
    Lattice dynamics of multiferroic BiFeO3 studied by inelastic x-ray scattering
    (IOP Publishing Ltd., 2013-03-13) Borissenko, E; Goffinet, M; Bosak, A; Rovillain, P; Cazayous, M; Colson, D; Ghosez, P; Krisch, M
    We report an experimental study of the phonon dispersion in BiFeO3 single crystals at ambient conditions by inelastic x-ray scattering (IXS). The phonon dispersions were recorded along several symmetry directions up to 35 meV. Our results compare favorably with first-principles calculations performed using density functional theory (DFT) within the local-density approximation (LDA). We resolve a discrepancy concerning the symmetry of the optical phonon branches observed by Raman spectroscopy, determine the energy of the lowest Raman and infrared silent mode, and derive a subset of the elastic moduli of BiFeO3. © 2011 IOP Publishing LTD.