Heavy fermion superconductors relaxation

Magnetic Ordering and Paramagnetic Relaxation in Heavy Fermion Superconductors... 

Mossbauer spectroscopy was applied to heavy fermion superconductors of UPd2Al3, URu2Si2, and UPt3. A common feature in these compounds is the observation of paramagnetic relaxation. However, the observation of the hyperfine field in their antiferromagnetic ordered states is different among them. The conclusions of the application of the Mossbauer spectroscopy to the heavy fermion superconductors are as follows ... 

The main experimental information that usually can be deduced from ESR experiments in metals are the g-shift and the linewidth broadening. Both quantities can be measured as a function of an external parameter, like temperature or pressure. The g-shift corresponds to the Knight-shift in NMR experiments and yields information about the static susceptibility. This review nicely documents how the experimental results on the g-shifts in metals provide direct and detailed information on the band structure. The ESR linewidth in metals is determined by the spin-lattice relaxation time and has to be compared to l/T) as deduced from NMR results. The linewidth is determined by the density of states, but in addition yields detailed information on the low-frequency spectrum of spin fluctuations. This is of high relevance in the field of high-Tc superconductors and heavy-fermion compounds. 

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