High-spin states in doubly odd ${}^{166}\mathrm{Tm}$ were investigated by means of in-beam $\gamma$-ray spectroscopy techniques using the multidetector array GASP. Excited states of ${}^{166}\mathrm{Tm}$ were populated using the ${}^{160}\mathrm{Gd}{(}^{11}\mathrm{B},5n)$ reaction at a beam energy of 61 MeV. Known rotational bands have been extended to higher spins and their configurations have been discussed. Alignments, band crossing frequencies, and electromagnetic properties have been analyzed in the framework of the cranking model. Signature inversion in the $\pi h_{9/2}\otimes \nu i_{13/2}$ structure is discussed. Calculations in the framework of the particle rotor model with $p-n$ interaction included have been able to reproduce the inversion. $E1\mathrm{}$ decay modes were observed in competition with $E2\mathrm{}$ intraband transitions.

• Received 3 July 2002

DOI:https://doi.org/10.1103/PhysRevC.66.044308