Hyperfine fields at lanthanide nuclei in the intermetallic compounds of RFe(2)

We have measured the hyperfine fields of Tm-169 in Tm0.02Gd0.98Fe2 and Tm0.02Y0.98Fe2 compounds using spin-echo NMR at 4.2 K. The results, together with complementary data obtained from other sources, are interpreted in terms of a simple model which involves hyperfine fields transferred from the lanthanide and iron ions. The effects of crystal-field quenching of the rare-earth moments in RFe(2) (R = heavy rare earth) and, where appropriate, magnetostriction, are estimated. We show that our simple model is satisfactory in the interpretation of hyperfine fields at lanthanide nuclei in the RFe(2) compounds. We obtain the coefficients K-p = 9.4(1.4) T, K-n = 3.5(0.9) T and beta = 15.8(1.6) T mu(B)(-1).