Abstract
We present neutron inelastic scattering measurements of the low-energy phonons in single crystal . The dispersions of the three acoustic phonon modes (LA along [100], along [010], and along and two low-energy optic phonon modes (LO and have been mapped out between and . Elastic constants are extracted from the phonon measurements. The energy linewidths of both TA phonons at the zone boundary clearly broaden when the system is warmed toward the magnetic ordering temperature . This suggests that the magnetic order and low-energy lattice dynamics in this multiferroic material are coupled.
- Received 8 October 2014
DOI:https://doi.org/10.1103/PhysRevB.91.064301
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