%0 Journal Article
%T Temperature-Dependent Interplay of Dzyaloshinskii-Moriya Interaction and Single-Ion Anisotropy in Multiferroic BiFeO$_3$
%A Jaehong Jeong
%A Manh Duc Le
%A P. Bourges
%A S. Petit
%A S. Furukawa
%A Shin-Ae Kim
%A Seongsu Lee
%A S-W. Cheong
%A Je-Geun Park
%J Physics
%D 2014
%I arXiv
%R 10.1103/PhysRevLett.113.107202
%X Low-energy magnon excitations in multiferroic BiFeO$_3$ were measured in detail as a function of temperature around several Brillouin zone centers by inelastic neutron scattering experiments on single crystals. Unique features around 1 meV are directly associated with the interplay of the Dzyaloshinskii-Moriya interaction and a small single-ion anisotropy. The temperature dependence of these and the exchange interactions were determined by fitting the measured magnon dispersion with spin-wave calculations. The spectra best fits an easy-axis type magnetic anisotropy and the deduced exchange and anisotropy parameters enable us to determine the anharmonicity of the magnetic cycloid. We then draw a direct connection between the changes in the parameters of spin Hamiltonian with temperature and the physical properties and structural deformations of BiFeO$_3$.
%U http://arxiv.org/abs/1408.2942v2