Pt195 nuclear-magnetic-resonance measurements were performed on aligned single-crystal whiskers of UPt3 for temperatures from 4 to 50 K. A special alignment technique allows us to produce samples with very good c-axis alignment and to work with the field parallel to the c axis with an excellent signal-to-noise ratio. Combining the Knight shift and spin-lattice-relaxation data, we show a continuous crossover from paramagnetic behavior above 40 K toward a degenerate-Fermi-liquid behavior below 5 K. Antiferromagnetic spin fluctuations appear to be responsible for this crossover process, and dominate all low-frequency magnetic properties of this compound. The anisotropy ratios of both the spin-lattice and the spin-spin relaxation rates are found to be temperature independent. Analyzing these ratios we find that the imaginary part of the dynamic spin susceptibility is slightly stronger in the basal plane.
ASJC Scopus subject areas
- Condensed Matter Physics