THE NUCLEAR-MAGNETIC-RESONANCE OF RU-99 AND RN-1O1 IN HEXAGONAL CLOSE-PACKED RUTHENIUM METAL

The nuclear magnetic resonance of Ru-99 and Ru-101 has been observed in hexagonal close-packed ruthenium metal. As both isotopes possess a nuclear quadrupole moment the field spectra show the characteristics for quadrupolar disturbed nuclear magnetic resonance. A computer simulation of the experimental spectra yields an electric field gradient of 1.09 +/- 0.06 x 10(17) V cm(-2) in good agreement with recent band structure calculations. The isotropic and axial Knight shifts, K-iso and K-ax deduced from these spectra are 0.49 +/- 0.02% and 0.045 +/- 0.002%, respectively. The rather high positive isotropic Knight shift is mainly due to the Van Vleck contribution, which is presumably also responsible for the rather strong anisotropy. The measurement of the spin-lattice relaxation of the isotopes Ru-99 and Ru-101, carried out at 4.2 K, yields spin-lattice relaxation times (T-1) of 3.7 +/- 0.2 s and 3.1 +/- 0.2 s, respectively.