High-resolution neutron spectroscopy of crystal-field excitations in uranium dioxide

Abstract

The authors report the results of a high-resolution inelastic neutron scattering measurement of the crystal-field excitations in uranium dioxide. All the dipole-allowed transitions within the lowest multiplet have been measured, allowing the first complete determination using neutron scattering of the crystal-field potential and J-mixing wavefunctions in an actinide compound. The splitting of the cubic crystal-field levels in the antiferromagnetic phase below TN=30.8 K is discussed, and compared with calculations made assuming either a 2-k or a 3-k magnetic structure.