Crystal field in ErGa3 – a neutron spectroscopy study

Abstract The splitting of the J =15/2 multiplet of Er 3+ in a cubic crystal field has been determined by inelastic scattering from a polycrystalline sample of ErGa 3 . On the basis of the observed intensities and their temperature variation we have been able to determine two crystal electric field (CEF) parameters required for cubic symmetry. Least-squares fits applied to the observed spectra taken at various temperatures gave crystal field parameters: B 4 =(7.15±0.05)×10 − 5 and B 6 =(1.28±0.05)×10 −6 meV yielding the Γ 7 doublet as a ground level with the overall splitting of 10.92 meV. The results are used to calculate the temperature-dependant zero-field magnetisation, the Schottky anomaly of the specific heat associated with the CEF splitting of Er 3+ in ErGa 3 , and the high-field magnetisation.