Electromagnetic properties of particle-hole excitations in nuclei near N = 50

The recoil-distance Doppler-shift (RDDS) and the IMPAD techniques were employed to determine lifetimes and magnetic moments of high-spin states in the semi-magic nuclei ⁹⁴Ru and ⁹⁵Rh. The experimental electromagnetic transition strengths allowed for the first time an unambiguous assignment of the experimentally observed densely lying levels to the states predicted in large-scale shell model calculations. In particular we succeeded to distinguish states where a neutron is excited across the N=50 shell closure from those where protons are promoted from the completely filled f_5/2, p_3/2 orbits into the g_9/2 orbit.