Magnetic excitations in ferromagnetic CeSb

Abstract

The magnetic excitation spectrum of ferromagnetic CeSb has been studied by neutron inelastic scattering at 4.2 K and 41.7 kOe for wave vectors along the <100≳ and <110≳ directions. Two dispersion branches have been resolved and analyzed in terms of crystal-field, bilinear and quadrupolar pair interactions. We find that the quadrupolar coupling is the dominant interaction and the bilinear exchange exhibits a strong directional anisotropy.