Exchange and crystal field in Sm-based magnets. I. Inelastic neutron scattering and high-field magnetization study of Sm2Fe17 and Sm2Fe17N3 - art. no. 064408

摘要

A peak is detected in the high-energy inelastic neutron scattering spectra of Sm2Fe17 and Sm2Fe17N3, which is associated with the intermultiplet transition in the 4f shell of samarium. The peak in the nitride Sm2Fe17N3 is situated at a lower energy (163 meV) as compared with the parent compound Sm2Fe17 (177 meV). The peak position provides direct information on the strength of the exchange field on Sm in both compounds: B-ex=380 and 270 T in Sm2Fe17 and Sm2Fe17N3, respectively. The 30% reduction in B-ex as a result of nitrogenating Sm2Fe17 is consistent with the earlier discovered similar effect in Gd2Fe17. High-field (B less than or equal to 50 T) magnetization curves have been measured on an oriented powder sample of Sm2Fe17N3 and analyzed using the newly determined B-ex. The leading crystal field parameter is thus found to be A(2)(0)[r(2)] = - 28 meV. [References: 17]