Magnetic properties of CeAs and CeSb deduced from neutron scattering data

Neutron inelastic scattering and powder diffraction techniques have been used to study the crystal field splitting and magnetic ordering properties of CeAs and CeSb. Powder diffraction data indicate a type 1 face-centred cubic magnetic ordering structure for CeAs with a moment of 0·68 μB±10% at 4·2 °K. This value demonstrates that the ground state of Ce3+ in CeAs is a doublet. Inelastic scattering measurements give directly a value of the crystal field splitting in this compound of 140±10 °K (12 meV). The powder diffraction data for CeSb could not be interpreted using any of the simple face-centred cubic types of antiferromagnetic ordering. The inelastic data show that the crystal field splitting is smaller than 25 °K (2·1 meV).