Thermal evolution of the full three-dimensional magnetic excitations in the multiferroic BiFeO3

Abstract

The idea of embedding and transmitting information within the fluctuations of the magnetic moments of spins (spin waves) has been recently proposed and experimentally tested. The coherence of spin waves, which describes how well defined these excitations are, is of course vital to this process, and themost significant factor that affects the spin-wave coherence is temperature. Here we present neutron inelastic scattering measurements of the full threedimensional spin-wave dispersion in BiFeO3, which is one of the most promising functional multiferroic material, for temperatures from 5K to 700K. Despite the presence of strong electromagnetic coupling, the magnetic excitations behave like conventional magnons over all parts of the Brillouin zone. At low temperature the spin-waves are well-defined coherent modes, described by a classical model for a G-type antiferromagnet. A spin-wave velocity softening is already present at room temperature, and more pronounced damping occurs as the magnetic ordering temperature TN \sim 640K is approached. In addition, a strong hybridization of the Fe 3d and O 2p states is found to modify the distribution of the spin-wave spectral weight significantly, which implies that the spins are not restricted to the Fe atomic sites as previously believed.

References in corpus (6)

• Electric-field control of spin waves at room temperature in multiferroic BiFeO3
• Temperature-dependent properties of the magnetic order in single-crystal BiFeO3
• Magnetic dispersion and anisotropy in multiferroic BiFeO3
• Optical coupling to spin waves in the cycloidal multiferroic BiFeO3
• Spin wave measurements over the full Brillouin zone of multiferroic BiFeO3
• Anharmonic Phonons and Magnons in BiFeO3

Cited by in corpus (12)

• Structure and spin dynamics of multiferroric BiFeO${}_3$
• Absolute cross-section normalization of magnetic neutron scattering data
• Magnetic Interactions in BiFeO${}_3$: a First-Principles Study
• Spin and lattice excitations of a BiFeO3 thin film and ceramics
• Field dependence of the Spin State and Spectroscopic Modes of Multiferroic BiFeO${}_3$
• Spin-Induced Polarizations and Non-Reciprocal Directional Dichroism of Multiferroic BiFeO${}_3$
• Ordered magnetism in the intrinsically decorated $j{}_{\mathrm{eff}}$ = $\frac{1}{2}$ $\alpha$-CoV${}_3$O${}_8$
• The Microscopic Model of BiFeO${}_3$
• Neutron inelastic scattering measurements of low energy phonons in the multiferroic BiFeO3
• The Magnetoelastic Distortion of Multiferroic BiFeO${}_3$ in the Canted Antiferromagnetic State
• Exceptional field dependence of antiferromagnetic magnons in LiFePO${}_4$
• Orientation Dependence of the Critical Magnetic Field for Multiferroic BiFeO${}_3$