RKKY formalism

For a localized spin system Bt f and T, can be treated within the RKKY formalism. According to Kropp et al. (1979) one finds... 

The RKKY formalism allows also to relate the changes in Neel temperature with those of the contact electron density as measured by isomer shift. The combination of eqs. (45) and (46) leads to... 

This is experimentally fulfilled with high precision (fig. 30). Because of the linear relation depicted in fig. 29, the same correlation exists for the changes in Bhf-The result of fig. 30 not only justifies the assumptions made above, but in particular it shows that the RKKY formalism is applicable here and that we deal with a localized... 

The residual depolarization rate in the absence of spin correlations is contained in k2 of eq. (68) and determined by the RKKY (4f-4f) and Korringa (4f-ce) interactions. Starting from a treatment of the transverse NMR relaxation rate Tf by Moriya (1956) and the common Korringa formalism (Korringa 1950) it was shown that the dynamic depolarization rate at high temperatures (when contact coupling is neglected) can be written as... 

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