Article

Dzyaloshinskii-Moriya Interaction: How to Measure Its Sign in Weak Ferromagnets?

JETP Letters (Impact Factor: 1.36). 09/2010; 92(6):383-387. DOI: 10.1134/S0021364010180050
Source: arXiv

ABSTRACT

Three experimental techniques sensitive to the sign of the Dzyaloshinskii-Moriya interaction are discussed: neutron diffraction,
Mössbauer γ-ray diffraction, and resonant x-ray scattering. Classical examples of hematite (α-Fe2O3) and MnCO3 crystals are considered in detail.

Download full-text

Full-text

Available from: E. N. Ovchinnikova
  • [Show abstract] [Hide abstract]
    ABSTRACT: The X-ray resonant diffraction in a stishovite crystal near the K absorption edge of silicon (E K = 1839 eV) is studied theoretically. For such a long wavelength, the only possible Bragg reflection is the 100 reflection, which is forbidden by the space group of the crystal. It can be excited solely due to anisotropy of the X-ray scattering amplitude. The crystal symmetry is used to determine the polarization and azimuthal dependence of the reflection intensity. Since this reflection is single, it can be detected upon diffraction from a powder, which substantially widens the possibilities of investigations. The numerical calculations of the energy dependences of the forbidden reflection intensity and the absorption coefficient demonstrate that the dipole-quadrupole, quadrupole-quadrupole, and dipole-octupole contributions to the resonant diffraction and absorption are small and that the dipole-dipole contribution is the most important one.
    No preview · Article · May 2011 · Journal of Experimental and Theoretical Physics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Spin-polarized current effect is studied on the static and dynamic magnetization of the antiferromagnet in a ferromagnet - antiferromagnet junction. The macrospin approximation is generalized to antiferromagnets. Canted antiferromagnetic configuration and resulting magnetic moment are induced by an external magnetic field. The resonance frequency and damping are calculated, as well as the threshold current density corresponding to instability appearance. A possibility is shown of generating low-damping magnetization oscillations in terahertz range. The fluctuation effect is discussed on the canted antiferromagnetic configuration.
    Preview · Article · Jun 2011
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Spin-polarized current effect is studied on the static and dynamic magnetization of the antiferromagnet in a ferromagnet - antiferromagnet nanojunction. The macrospin approximation is generalized to antiferromagnets. Canted antiferromagnetic configuration and resulting magnetic moment are induced by an external magnetic field. The resonance frequency and damping are calculated, as well as the threshold current density corresponding to instability appearance. A possibility is shown of generating low-damping magnetization oscillations in terahertz range. The fluctuation effect is discussed on the canted antiferromagnetic configuration. Numerical simulation is carried out of the magnetization dynamics of the antiferromagnetic layer in the nanojunction with spin-polarized current. Outside the instability range, the simulation results coincide completely with analytical calculations using linear approximation. In the instability range, undamped oscillations occur of the longitudinal and transverse magnetization components.
    Preview · Article · Dec 2011
Show more