Revised magnetic properties of CuFeO2 -: a case of mistaken identity

We propose a new model for the understanding of the magnetic properties of CuFeO2, which differs significantly from the generally accepted two-dimensional Ising model. We show that a Heisenberg model with a relatively weak anisotropy gives a much better description of all the magnetic data available for CuFeO2. The model is self-consistent; it allows one to determine for the first time a set of parameters for the exchange interactions and magnetic anisotropy in this frustrated magnetic system. The model is backed up by single-crystal measurements of susceptibility, magnetization and specific heat as a function of magnetic field and temperature.