Spin waves and the origin of commensurate magnetism in Ba2CoGe2O7
arXiv:cond-mat/0302592 · doi:10.1103/PhysRevB.68.024428
Abstract
The square-lattice antiferromagnet Ba2CoGe2O7 is studied by means of neutron diffraction and inelastic scattering. This material is isostructural to the well-known Dzyaloshinskii-Moriya helimagnet Ba2CuGe2O7, but exhibits commensurate long-range Neel order at low temperatures. Measurements of the spin wave dispersion relation reveal strong in-plane anisotropy that is the likely reason for the suppression of helimagnetism.
5 pages 3 figures, submitted to Phys. Rev. B