Study of the nitrogen diffusion mechanism in R2Fe17

Previously, nuclear magnetic resonance experiments and diffusion calculations have indicated that the distribution of nitrogen atoms in a Y2Fe17Nx particle with intermediate N content is characterized by a nitrided region and an unnitrided region. In order to directly detect this two‐region configuration, x‐ray diffraction experiments have been carried out on systematically ground nitrogenated samples. Furthermore, x‐ray diffraction and 89Y nuclear magnetic resonance on vacuum‐annealed samples show that the two‐region configuration is stable, and that the nitrogen atoms do not diffuse further into the particle. Thermal conductivity detection measurements indicate that only 5% of the inserted N atoms can be released by vacuum annealing at the nitrogenation temperature.