New neutron-rich nucleiZr103,104and theA∼100 region of deformation

Partial decay schemes in the neutron-rich nuclei ${}_{}{}^{103}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{104}{}_{}{}^{}\mathrm{Zr}$ have been measured for the first time and rotational bands in ${}_{}{}^{100–102}{}_{}{}^{}\mathrm{Zr}$ have been extended to spins of up to 10ħ by observing prompt γ rays from the spontaneous fisson of ${}_{}{}^{248}{}_{}{}^{}\mathrm{Cm}$. These nuclei are among the most deformed known at low spin and excitation energy. The level structures in the odd-A nuclei show that the ${\mathit{h}}_{11/2}$ intruder orbital plays an important role in stabilizing the deformation in this region.