The high-spin states of 157Yb have been studied via the 144Sm(16O, 3n) reaction at 16O energy of 90 MeV using techniques of in-beam γ-ray spectroscopy. Measurement of γ-γ-t coincidences was performed with 11 BGO (AC) HPGe detectors. Based on the measured results of γ-γ coincidences, γ-ray anisotropies and DCO ratios, the level scheme for 157Yb was established. The shape co-existence and structural evolution of the νi13/2 band with increasing angular momentum in 157Yb have been discussed. The systematics of the νi13/2 bands in the N=87 odd-A isotones have been compared.

High-spin states in doubly odd 170Re have been populated via the 142Nd(32S, p3nγ) reaction at beam energies of 155 and 166 MeV. K X-γ and γ-γ coincidences have been measured using a detector array consisting of 12 high-purity germanium detectors with BGO suppressors. A rotational band is identified and assigned to 170Re for the first time. This band is proposed to be built on the πh11/2⊗νi13/2 two-quasiparticle configuration by comparing the band properties with known bands in neighboring nuclei and the cranked-shell model calculations.

High-spin states in the odd-odd 172Re have been investigated via the 149Sm(27Al, 4nγ)172Re reaction through excitation functions, x-γ and γ-γ coincidence measurements. A level scheme consisting of three rotational bands has been identified for the first time extending the high-spin studies of A～160 odd-odd nuclei to the currently lightest rhenium isotope. The three bands have been assigned to be built on the πh11/2⊗νi13/2, πh9/2⊗νi13/2, and p1/2−[541]⊗ν1/2−[521] configurations according to their rotational properties in quasiparticle alignments, signature splitting, in-band B(M1)/B(E2) ratios, level spacing systematics, band crossing frequencies, as well as the existing knowledge in neighboring nuclei. Low-spin signature inversion has been confirmed in the first two bands due to the observation of signature crossing at high-spin states. The general features of inversion phenomenon in the semidecoupled bands are presented and discussed with reference to theoretical calculations of two quasiparticle plus rotor model including p-n interactions.

High spin states in 174Re have been investigated via the 152Sm (27Al, 5nγ) 174Re reaction. Gamma-ray excitation functions, x-γ and γ-γ coincidences have been measured. Two rotational bands built on the πh9=2⊗νi13=2 and πh11=2⊗νi13=2 con gurations have been identi ed and extended up to high-spin states. The relative spin and parity of the band levels have been unambiguously xed due to observations of several inter-band transitions. Both the bands show the low-spin signature inversion, which is consistent with systematic expectations for the high-j two-quasiparticle bands in the A=170 mass region.

An effort has been made to search for the decoupled bands in odd-odd 174Re via the 159Tb(20Ne, 5nγ)174Re reaction through excitation functions, K x-γ and γ-γ coincidence measurements. The doubly decoupled band and the semidecoupled one have been found in this work. Their quasiparticle conØgurations are proposed to be π1=2-[541]⊗ν1=2-[521] and π1=2-[541]⊗νi13=2, respectively, according to the characteristics of band structures in this mass region. Another band with strongly coupled character is also reported.