Site occupancy of Sm in (Nd1-xSmx)5(Fe1-yTiy)17
Abstract
The ferromagnetic compound Nd5Fe17 has a large average Fe moment (2.1 μB), a reasonably high Curie temperature (503 K), but basal plane spin orientation. Partial replacement of Nd by Sm leads to a uniaxial spin arrangement with substantial anisotropy field. Natural Sm has a large neutron absorption cross section (5650 b) which is usually thought to prevent neutron diffraction measurements unless Sm is replaced by a separated isotope with low absorption. However, the unique geometry of the MURR neutron powder diffractometer allows measurements on thin samples and data have been successfully collected on samples with up to about 50% Sm (Nd2.5Sm2.5Fe17). Samples prepared without Ti contain the 2:17 phase as well as the 5:17 phase, while those prepared with Ti have a very high concentration of the 5:17 phase which forms more readily (with minor amounts of TiFe2). The locations of Sm atoms in these compounds have been determined. These results may provide important information about the crystal fields at different sites in the 5:17 phase and suggest improved routes for synthesis of this potentially useful compound.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- May 2000
- DOI:
- 10.1063/1.372814
- Bibcode:
- 2000JAP....87.6704C
- Keywords:
-
- 75.50.Bb;
- 61.66.Dk;
- 75.30.Kz;
- 75.30.Cr;
- 75.50.Ww;
- 75.25.+z;
- 71.70.Ch;
- Fe and its alloys;
- Alloys;
- Magnetic phase boundaries;
- Saturation moments and magnetic susceptibilities;
- Permanent magnets;
- Spin arrangements in magnetically ordered materials;
- Crystal and ligand fields