CEF states in heavy-fermion superconductor UPd2Al3

The CEF-like excitations in UPd2Al3 revealed in neutron-scattering studies have been found consistent with earlier prediction on basis of the overall temperature dependence of the specific heat. The specific heat analysis yields 5 doubler states at energies 0, 100, 150, 350 and 600 K associated with the U3+ configuration. In fact, these states are similar to those observed in isostructural NdNi5 though the overall CEF splitting is more than two times bigger. The observation of the localized states by such different techniques and their consistency provides strong argument for the applicability of the crystal-field (CEF) theory to (some) actinide compounds like it was found for UGa2 and NpGa2. (C) 2000 Elsevier Science B.V. All rights reserved.