Magnetic properties of (Sm/sub 1-x/R/sub x/)/sub 2/Fe/sub 17/N/sub y/ (R=Dy, Er) compounds

• Published in: 1992. Digests of Intermag. International Magnetics Conference p. 197
• Main Authors: Teguo, O., Lu Yi, Tang, N., Wu, J.X., Mingjun Yu, Li, Q.A., Zhao, R.W., Yang Fu-ming
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1992
• Subjects: Erbium; Iron; Magnetic properties; Samarium
• ISBN: 0780306376; 9780780306370
• DOI: 10.1109/INTMAG.1992.696380

The effects of Dy and Er substitution for Sm on the structure and magnetic properties of Sm 2 Fe 17 and Sm 2 Fe 17 N y compounds have been studied. X-ray diffraction measurements showed that the structure type changes from Th 2 Zn 17 type to Th 2 Ni 17 with the increase of Dy and Er contents. The X-ray diffraction on magnetically aligned powder samples of (Sm 1-x R x l 2 Fe 17 N y (R=Dy, Er; x=0, 0.2, 0.4, 0.6, 0.8, 1.0) compounds showed that the easy magnetization axis maintained along the c-axis up to x=0.6 and x=0.8 at room temperature for R=Dy and R=Er, respectively. The lattice and magnetic parameters are listed in Table 1. It can be seen that the replacement of Sm by Dy or Er results in a decrease in Curie temperature and saturation magnetization in the nitrides compounds, with the increasing x. The uniaxial anisotropy observed for Sm 2 Fe 17 N y is weakened by replacing Sm with Dy or Er. The weakening is more fast in the case of Dy. This may be due to the fact that the Er, like Sm, possesses second order Stevens coefficient aJ, whereas Dy has negative aJ, so the crystal field interaction of Dy 3+ is opposite in sign of that of Sm 3+ , whereas the Er 3+ has same sign with Sm 3+ in crystal field interaction. The spin reorientation temperatures were determined from 1.5K to Curie temperature by means of ac-susceptibility measurement and thermomagnetic analysis, Spin reorientation has not been found in (Sm 1-x Er x ) 2 Fe 17 N y compounds, except for Er 2 Fe 17 N y . A tentative spin phase diagram for the (Sm 1-x Dy x ) 2 Fe 17 N y series is presented.