2005/06/03 by Takatsugu Masuda, T. Masuda, A. Zheludev +5
Engineering · Physics and Astronomy · #Advanced Condensed Matter Physics #Magneto-Optical Properties and Applications #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.72.094434
9 pages, 11 figures
arxiv created 2005/06/03 · openalex publication_date 2005/09/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Magnetic excitations in a weakly coupled spin dimers and chains compound Cu2Fe2Ge4O13 are measured by inelastic neutron scattering. Both structure factors and dispersion of low-energy excitations up to 10\phantom\rule0.3em0exmeV energy transfer are well described by a semiclassical spin wave theory involving interacting Fe3+(S=5∕2) chains. Additional dispersionless excitations are observed at higher energies, at \ensuremathℏ\ensuremathω=24\phantom\rule0.3em0exmeV, and associated with singlet-triplet transitions within Cu2+ dimers. Both types of excitations can be understood by treating weak interactions between the Cu2+ and Fe3+ subsystems at the level of the mean-field random phase approximation. However, this simple model fails to account for the measured temperature dependence of the 24\phantom\rule0.3em0exmeV mode.