K-isomers and aspects of nuclear structure

Gamma-ray spectroscopy measurements with Gammasphere and multi-nucleon transfer reactions with heavy beams provide a means of accessing deformed nuclei at stability, or on the neutron-rich side of the stability line. New results on the discovery of high-K isomers in the Er-Tm-Yb-Lu region are discussed with a focus on the energy systematics and the factors which may govern K-purity and therefore K-hindrances. These include random-mixing in regions of high level density, specific Coriolis mixing in configurations involving the i _13/2 neutron configuration, and chance degeneracies between an individual high-K state and a specific collective state which provide an opportunity to extract effective mixing matrix elements between states of very different-K.