Assessment of Directionally Solidified Eutectic Sm–Fe(Co)–Ti Alloys as Permanent Magnet Materials

Journal Article · 28 May 2023 · IEEE Transactions on Magnetics

DOI: https://doi.org/10.1109/tmag.2023.3280849 · OSTI ID:1975064

Gabay, Alexander M.  ^[1]; Han, Chaoya ^[2]; Ni, Chaoying  ^[2]; Hadjipanayis, George C. ^[3]

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1. Univ. of Delaware, Newark, DE (United States); University of Delaware
2. Univ. of Delaware, Newark, DE (United States)
3. Univ. of Delaware, Newark, DE (United States); Northeastern Univ., Boston, MA (United States)

Sm–Fe–Ti and Sm–Fe0.8Co0.2–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 [001] 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.

• Research Organization: Univ. of Delaware, Newark, DE (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0022168
• OSTI ID: 1975064
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 11 Vol. 59; ISSN 0018-9464
• Publisher: Institute of Electrical and Electronics Engineers. Magnetics GroupCopyright Statement
• Country of Publication: United States
• Language: English