The origin of the enhancement of magnetic properties in Sm2Fe17Nx (0<x?3)

Abstract The Sm 2 Fe 17 N x (1.2 x 2 Fe 17 , the Sm 2 Fe 17 N 3 and a small component with the HF of 5 T. The fractions of the phases depend on the nitrogen contents and the annealing durations. No intermediate HF was detected in the samples of x =1.1–2.1 regardless of the annealing duration. With the crystal structural consideration of the Th 2 Zn 17 structure, the intermediate nitrogen content regions that could be detected by the X-ray diffraction and the magnetization measurements, should be magnetically composed of the mixtures of Fe–N and/or Fe–Fe–N hybridizations whose numbers are smaller than the case of Sm 2 Fe 17 N 3 . The chemical bonds formation in the system should be an important factor for the enhancement of the magnetic properties with nitrogen uptake, contrary to the facts expected and understood in the previous studies.