CALCULATED SPIN-LATTICE RELAXATION OF RU-103 COMPARED WITH LOW-TEMPERATURE QUADRUPOLE ORIENTATION MEASUREMENTS

The spin-lattice relaxation time T1 in Ru-103 has been determined on t he basis of the Dirac theory and strict relativistic band structure ca lculations. The low temperature relaxation time T1' of Ru-103 in an ax ially symmetric quadrupole field and the quadrupole moment Q have been measured by Green and Stone using the technique of low temperature qu adrupole orientation. For the usual reference value T1 T, which corres ponds to relaxation in a Zeeman spectrum, they obtain 39(6) sK, which exceeds our value by 134%. This large discrepancy is attributed to the fact that the spin relaxation by direct quadrupole scattering of cond uction electrons, the so-called Mitchell contribution, is dominant. Ac cording to our calculations it amounts to 81 % of the total relaxation rate. This contribution could not be included in the evaluation of th e experimental data.