Magnetic anisotropy of R2Fe17Nx compounds

A nearly perfect magnetic alignment of R2Fe17Nx powders (<20 μm) with respect to the c axis was obtained by using the sample-rotation magnetic-alignment technique. The magnetization from 4.2 to 300 K was measured on the magnetically aligned samples by means of the sample-extraction method in a static field up to 23 T. The Fe-sublattice anisotropy was determined by analyzing the magnetization curves of R2Fe17Nx with R=Y, Ce, Gd, and Lu. Compared to corresponding R2Fe17 compounds, the Fe-sublattice anisotropy of R2Fe17Nx is substantially lower. For R2Fe17Nx with R=Pr, Nd, Sm, Tb, and Er, the magnetization curves in the [001] direction show no anomaly whereas a first-order magnetization process (FOMP) was detected in corresponding R2Fe17 compounds, suggesting that the FOMP transition in R2Fe17 is suppressed upon nitrogenation.