We present a detailed study of the magnetic structure and spin waves in the Fe jarosite compound KFe3(SO4)2(OH)6 for the most general Hamiltonian involving one- and two-spin interactions which are allowed by symmetry. We compare the calculated spin-wave spectrum with the recent neutron scattering data of Matan {\it et al.} for various model Hamiltonians which include, in addition to isotropic Heisenberg exchange interactions between nearest (J1) and next-nearest (J2) neighbors, single ion anisotropy and Dzyaloshinskii-Moriya (DM) interactions. We concluded that DM interactions are the dominant anisotropic interaction, which not only fits all the splittings in the spin-wave spectrum but also reproduces the small canting of the spins out of the Kagom\'e plane. A brief discussion of how representation theory restricts the allowed magnetic structure is also given.
@article{arxiv.cond-mat/0603280,
title = {Magnetic Structure and Spin Waves in the Kagom\'{e} Jarosite compound ${\bf KFe_3(SO_4)_2(OH)_6}$},
author = {T. Yildirim and A. B. Harris},
journal= {arXiv preprint arXiv:cond-mat/0603280},
year = {2009}
}
Comments
23 pages, 17 figures, submitted to Phys. Rev. B (March 2006)