MEASUREMENTS OF SPECTROSCOPIC QUADRUPOLE-MOMENTS OF NEUTRON-DEFICIENTAU ISOTOPES WITH QUADRUPOLE-INTERACTION-RESOLVED NMR-ON

We report on measurements of quadrupole-interaction-resolved nuclear m agnetic resonance on oriented nuclei (QI-NMR-ON) of 3/2+ Au-193 (T1/2 = 17.5 h) and 3/2+ Au-195 (T1/2 = 183 d) in hcp-Co. The results for th e magnetic and electric hyperfine splittings are: Au-193: nu(M) = 67.7 2(2) MHz; nu(Q) = -15.69(4) MHz; Au-195: nu(M) = 71.65(1) MHz; nu(Q) = -14.34(2) MHz. Taking into account hyperfine anomalies, the magnetic moments are deduced to be: mu(Au-193) = 0.1396(6) mu(N); mu(Au-195) = 0.1487(6) mu(N). With the known quadrupole moment of Au-193, Q = +0.66 4(20), b, the electric field gradient of Au in hcp-Co is deduced to be eq = - 0.977(29) X 10(17) V/cm2, with which Q(Au-195) = +0.607(18) b is obtained for the spectroscopic quadrupole moment of Au-195. In addi tion, the experimentally known quadrupole splitting frequencies of 186 Au, Au-198 and Au-199 in hcp-Co can be reinterpreted, giving the resul ts: Q(186Au) = +3.14(16) b; Q(Au-198) +0.640(19) b; Q(Au-199) = +0.510 (16) b.