A temperature shift of energy levels in the main Ce3+ multiplet in the concentrated Kondo-system Ce3 Al

Slow neutron inelastic scattering (SNIS) was used for the energy structure study of the main multiplet 2 F5/2 Ce3+ in the crystalline electric field (CEF) of the Ce3 Al compound. It was the first observation of the CEF energy level lowering by 30 % at temperature rising from 100 to 300 K. This shift of the levels was accompanied with a decrease of inelastic transition line widths. The third observed moment for Ce3 Al was the presence of two quasielastic lines with a different half-width in the SNIS spectrum, revealing two spin fluctuation types with a different spin relaxation time