| Using a combination of inelastic neutron scattering measurements (a-b) and theoretical modeling (c), we demonstrate that lattice distortions play an important role in determining the magnetic ground state of Ga-doped CuFeO2. With a slight modification of the exchange parameters from pure CuFeO2 and by adjusting the anisotropy and distortion energies, we achieve remarkable agreement between the observed and predicted dynamical “fingerprint” of the multiferroic phase. This complex ground state provides an alternative way to realize multiferroic coupling, where displacements of the oxygen atoms severely distort the spin configuration. Many other frustrated magnets with rhombohedral or hexagonal symmetries may also exhibit the same form of multiferroic coupling as doped CuFeO2. The symmetry of these materials makes them excellent candidates for exotic magnetoelectric control. This work was done by J. Haraldsen and R. Fishman in collaboration with F. Ye and J. Fernandez-Baca at the Neutron Scattering Science Division, and Prof. T. Kimura group at Osaka University. Phys. Rev. B 82, 020404(R) (2010). |
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