A high-resolution neutron scattering investigation of the crystal field splittings of UO2

Abstract

Measurements of the crystal field excitations of UO₂ have been made using the high-energy transfer spectrometer of the U.K. spallation neutron source, ISIS. Scans with high resolution have revealed splittings due to exchange interactions and lattice distortions in the antiferromagnetic phase. A new crystal field potential for the U⁴⁺ ion is deduced, with important implications for the thermodynamic properties of the compound.