Abstract
The spin-wave excitations of the geometrically frustrated triangular lattice antiferromagnet have been measured using high resolution inelastic neutron scattering. Antiferromagnetic interactions up to third nearest neighbors in the plane (, , , with and ), as well as out-of-plane coupling (, with ) are required to describe the spin-wave dispersion relations, indicating a three-dimensional character of the magnetic interactions. Two energy dips in the spin-wave dispersion occur at the incommensurate wave vectors associated with multiferroic phase and can be interpreted as dynamic precursors to the magnetoelectric behavior in this system.
- Received 8 May 2007
DOI:https://doi.org/10.1103/PhysRevLett.99.157201
©2007 American Physical Society