Magnetic interactions in the monoclinic ludwigite Cu

The system Cu2FeO2BO3 is an oxyborate belonging to the family of the ludwigites. In this paper we present AC susceptibility, magnetization measurements and Mössbauer spectroscopy on this material which allows for a complete characterization of its complex magnetic behavior. We find an hierarchy of interactions which clearly defines three regimes with decreasing temperature. These are associated with, the freezing of the Fe moments, the antiferromagnetic ordering of the Cu sub-lattice and finally the coupling between both systems