Transition strengths in odd-odd ⁸⁶Nb

High angular momentum states in odd-odd ⁸⁶Nb were populated through the ⁵⁸Ni(³²S,3pn) reaction at 135 MeV. Recoiling ⁸⁶Nb nuclei were stopped in a thick Ta backing. Prompt multi-γ coincidences with evaporated charged particles were detected using the full array of Gammasphere and the Microball. Mean lifetimes of 51 levels in ⁸⁶Nb were measured using the Doppler-shift attenuation method. Strongly alternating magnetic dipole transition strengths were observed in the yrast positive-parity bands. Most of the transition quadrupole moments inferred from the lifetimes lie in the range of 1 to 2.7 e b, which would correspond to quadrupole deformations β₂ of 0.10 to 0.27 in a rotational model. Comparison with Hartree-Fock-Bogoliubov cranking calculations suggests triaxial to oblate shapes.