Abstract
The g-factors of the 2 1 + states in 144, 146 Ba have been measured using the perturbed angular correlation method. The results are combined with existing experimental data for the neutron-rich Nd, Sm and Gd isotopes and discussed in the framework of the neutron proton interacting boson model. It is shown that the assumption of a drastic change in the effective proton boson number around N = 88, proposed in an earlier study, allows all the results to be explained in a simple framework involving constant values of the boson g-factors. © 1983.