Paramagnetic Relaxation for Erbium in Copper

Abstract

The perturbations acting on rare — earth ions in solids are not well understood. Waddington et al.¹ ) have studied the perturbed angular correlations on rare — earth ions implanted into copper lattices after Coulomb excitation (IMPAC). They conclude that a pure magnetic interaction as calculated by Blume² ) seems to explain most of the features of the measured perturbations. However, the results can also be explained in the framework of the theory of Abragam and Pound ), if two relaxation times are assumed to result from different lattice locations of the implanted ions, or if both magnetic and electric time — dependent interactions are present. The latter could result from unknown crystalline effects. Heestand et al.⁴) have recently performed a time — differential measurement on ¹⁶⁶Er in copper, and they have not observed the shape as predicted by the theory of Blume.