Crystal Field Model of the Magnetic Properties of URu2Si2

Abstract
We propose a model based on quadrupolar ordering of localized f electrons to explain the 17.5 K phase transition of URu2 Si2. The tiny staggered magnetic moment observed by neutron scattering is interpreted as a weak secondary effect associated to the symmetry-breaking perturbation. The model is able to account for the observed behavior of the linear and nonlinear susceptibilities throughout the transition. A connection with the quadrupolar Kondo theory is proposed.