NMR OF ND AND SM IN ND2FE14B AND SM2FE14B

The spin-echo NMR spectra of Nd-143, Nd-145, Sm-147 and Sm-149 in poly crystalline samples of Nd2Fe14B and Sm2Fe14B measured at 4.2K are pres ented. Well resolved quadrupole subspectra are assigned to the rare ea rth sites 4f and 4g in the compounds. The corresponding values of the quadrupole splitting and hyperfine fields are analyzed in terms of the contributions depending on the rare earth type as well as local symme try and environment of the sites. From the quadrupole splitting the 4f and the lattice contributions to the electric neld gradient st Nd and Sm nuclei are derived. On this basis the crystal electric field coeff icients A(2)0 for both rare earth sites are obtained and compared to t hose obtained in other measurements.