The medium spin, near yrast states of the $\mathrm{fpg}$ shell nuclei ${}^{58}\mathrm{Ni},$ ${}^{61}\mathrm{Cu},$ and ${}^{61}\mathrm{Zn}$ have been studied following the fusion evaporation of a ${}^{24}\mathrm{Mg}$ beam and a ${}^{40}\mathrm{Ca}$ target. Discrete transitions were unambiguously identified using the AYEBALL gamma-ray array in conjunction with the Argonne fragment mass analyzer and a split anode ionization chamber. The decay schemes of ${}_{28}^{58}\mathrm{Ni},$ ${}_{29}^{61}\mathrm{Cu},$ and ${}_{30}^{61}\mathrm{Zn}$ have been extended with the results of gamma-gamma coincidences and directional correlation from oriented state measurements used to determine the level excitation energies, spins, and parities of a number of near yrast states. The decay schemes deduced are compared with previous work and interpreted in terms of shell model calculations, with a restricted basis of the $f_{5/2},$ $p_{3/2},$ $p_{1/2}$ orbitals outside a ${}_{28}^{56}\mathrm{Ni}$ core, and either the $g_{9/2}$ orbital with a closed core, or $f_{7/2}$ excitations from the core.

• Received 7 June 1999

DOI:https://doi.org/10.1103/PhysRevC.60.064308