Magnetic Moments and Initial Susceptibilities of f‐Electron States Experiencing a Crystal Field of Cubic Symmetry

The effect of perturbation to the second order caused by a magnetic field H on the energy levels of an f‐electron situated in a crystal field of cubic symmetry is calculated. This development is of particular interest in the understanding of magnetic properties of f‐electrons: the term in H gives the individual magnetic moment of the considered sub‐level and the term in H2 the corresponding Van Vleck susceptibility. The cases of H parallel respectively to the three principal crystallog‐ raphic directions are considered. The three terms of the energy development are tabulated for all J from 2 to 8 in the cases of purely fourth and sixth order crystal field.