The M1 properties of even ${}_{}{}^{182\mathrm{-}186}{}_{}{}^{}\mathrm{W}$ isotopes are investigated in the interacting boson model-2 (IBM-2). The E2/M1 mixing ratios, g factors, and summed M1 strength are calculated. A least-squares fit of the excitation energies is used to fix the IBM-1 projected Hamiltonian parameters, while the F-spin-breaking terms are adjusted to reproduce the M1 properties of low-lying states. The influence of F-spin mixing on the summed M1 strength is studied using the coherent state technique in perturbation theory. When the standard boson g factors are used, the M1 properties of the low-lying states are described satisfactorily, but the summed M1 strengths are found to be larger than present experimental values. Possible g factor adjustment, which reconciles the calculated and experimental M1 strength, is discussed. © 1996 The American Physical Society.

• Received 20 December 1995

DOI:https://doi.org/10.1103/PhysRevC.53.2794