High-spin g factors and proton alignment in 180,182,184Pt

The average g factors of high-spin states in 180,182,184Pt were measured by the transient-field technique. In all three isotopes the quasicontinuum g factor at an angular momentum of ∼20ℏ is 〈g〉∼0.37. This contrasts with similar measurements on other nuclei that have 70⩽Z⩽80, where typical values of 〈g〉∼0.22 have been attributed to the influence of quasineutron alignments. Evidently proton and neutron configurations are about equally important at high spin in the Pt isotopes near mid-shell. This inference is consistent with the discrete spectroscopy, including the contention, supported by gK−gR values, that h9/2 proton pairs align along with the i13/2 neutrons at rotational frequencies of ℏω≈0.3 MeV in 184Pt. Links between the quasicontinuum g factors and features in the discrete spectroscopy are explored by comparing and contrasting the behavior of 184Pt and 166Hf.