Assessment of Directionally Solidified Eutectic Sm–Fe(Co)–Ti Alloys as Permanent Magnet Materials
IEEE Transactions on Magnetics
Sm–Fe–Ti and Sm–Fe 0.8 Co 0.2 –Ti alloys were prepared via arc-melting and directionally solidified on a water-cooled copper hearth. The as-solidified alloys featured cells of the Sm(Fe,Co,Ti) 12 –Ti(Fe,Co) 2+δ –(α-Fe) lamellar eutectic. The lamellae of Sm(Fe,Co,Ti) 12 phase with a crystal structure of the ThMn12 type were less than 0.2 μm thick, and had their  easy-magnetization directions oriented along the temperature gradient of the solidification. The eutectic microstructure led to an increased coercivity, especially in the Co-added alloys. Below 250 °C, this coercivity was found not to vary much with temperature with a temperature coefficient of -0.18 %/°C. However, the modest absolute values, reaching only 0.7 kOe, are insufficient for utilization of the directionally solidified alloys as anisotropic permanent magnets.
This article was originally published in IEEE Transactions on Magnetics. The version of record is available at: https://doi.org/10.1109/TMAG.2023.3280849. © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This article will be embargoed until 05/29/2025.
magnetic materials, metallurgy, permanent magnets, samarium compounds, ThMn12 type
A. M. Gabay, C. Han, C. Ni and G. C. Hadjipanayis, "Assessment of Directionally Solidified Eutectic Sm–Fe(Co)–Ti Alloys as Permanent Magnet Materials," in IEEE Transactions on Magnetics, doi: 10.1109/TMAG.2023.3280849.