g factors of the 21+ and 41+ states in 92,94Zr have been measured via Coulomb excitation of isotopically pure 92,94Zr beams in inverse kinematics in combination with the transient field technique. The high precision results, g(92Zr; 21+ = -0.180(10) and g(94Zr; 21+ = -0.329(15) as well as the new data on the 41 state, g(92Zr; 41+) = -0.50(11), provide, for the first time, clear evidence of the dominant role of d5/2 neutrons in the wave functions of these nuclei just above the N = 50 shell closure. Moreover, the data imply increased purity of the d5/2 neutron component in the wave function with increasing spin. © 1999 Published by Elsevier Science B.V. All rights reserved.

Magnetic dipole and electric quadrupole moments have traditionally been critical in the determination of the microscopic wave functions of particular nuclear states. Measurements on nuclei at high spin and energy, as well as on nuclei in superdeformed states have yielded a wealth of information on their structure. The techniques developed for these measurements are now being extended to the study of nuclei far-from-stability such as those which will be accessible via reactions with radioactive beams. Very precise determinations of the magnetic moments of the 21+ states of Cr, Ti, Zr, Se and Nd isotopes, recently carried out via "projectile excitation", place very tight constraints on existing nuclear models, from single particle calculations in the 1fp shell to extended IBM models, and further highlight the importance of the interplay between single particle and collective excitations across the table of isotopes. The experimental results will be presented and compared with theoretical calculations.