Hyperfine fields at lanthanide nuclei in the intermetallic compounds of RFe2

We have measured the hyperfine fields of 169Tm 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 RFe2 (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 RFe2 compounds. We obtain the coefficients Kp = 9.4(1.4) T, Kn = 3.5(0.9) T and β = 15.8(1.6) T μB-1. (author)