Measurement of the magnetic behaviour of 147Eu and 149Eu in cerium and platinum

The local magnetism at europium in platinum and in cerium was studied using perturbed angular correlation (PAC) spectroscopy. In platinum, europium shows the electronic properties of the trivalent status, which has a non-magnetic ground state (J=0). As a consequence, the Van Vleck contributions from the complete multiplet-level system predominantly determine the magnetic behaviour. In cerium, the measured data are close to the predictions for divalent europium. Here, only the electronic ground state, the pure spin state (J=5/2), has to be taken into account. The measurements were done utilising the isomeric 11/2− nuclear levels in 147Eu and 149Eu at 625 and 496 keV, respectively, after the precursors had been produced at the ion beam laboratory ISL Berlin or the on-line mass separator ISOLDE in Geneva.