Document Type
Article
Publication Date
10-9-2025
Publication Title
Journal of Alloys and Compounds
Abstract
Optimizing SmCo(5-)based nanocomposites for high-temperature magnetic applications requires balancing coercivity and saturation magnetization, properties often compromised by grain coarsening, oxidation, and secondary phase formation during conventional sintering. This study investigates the microstructural evolution and magnetic properties of SmCo5 and SmCo5-Fe composites processed via high-energy ball milling followed by spark plasma sintering at 900 degrees C and 1000 degrees C, a route designed to retain the nanostructure while enabling rapid densification compared to conventional sintering. A suite of characterization techniques, including electron microscopy, X-ray diffraction, magnetometry, Magneto-optical Kerr effect, and magnetic force microscopy, reveals the extent of consolidation, phase composition, and change in magnetic response due to the presence of different phases such as SmCo5, Sm2Co17, Sm2O3, and CoFe. SmCo5 sintered at 900 degrees C exhibits a coercivity of 37.4 kOe and saturation magnetization of 77.2 emu/g, with phase fractions of similar to 64 % SmCo5 (hard phase, H-c approximate to 44 kOe) and similar to 36 % Sm2Co17 (soft phase, H-c = 7.5 kOe). At 1000 degrees C, coercivity increased slightly to 38.0 kOe while magnetization decreased to 71.1 emu/g, with similar to 65 % SmCo5 (Hc ti 45 kOe) and similar to 35 % Sm2Co17 (H-c = 5.5 kOe). Fe addition promoted CoFe phase formation, raising magnetization to 133 emu/g, but reducing coercivity to similar to 45-80 Oe. These results highlight the role of Fe in tuning magnetic interactions and emphasize the strong influence of processing temperature in controlling phase evolution, which could offer a pathway to optimize SmCo5-based nanocomposites for high-temperature magnetic applications.
Recommended Citation
Ishrak, Farhan; Lastovich, Michael; Tsai, Fu-Yun; Perkins, Charles IV; Baldino, Henri; Helmer, Alex; Rego, Sean; Karki, Sanoj; Hedlund, Daniel; Gupta, Rajeev; and Borkar, Tushar, "Microstructural Evolution and Magnetic Properties of Spark Plasma Sintered SmCo5 and SmCo5-Fe Composites" (2025). Mechanical Engineering Faculty Publications. 443.
https://engagedscholarship.csuohio.edu/enme_facpub/443
DOI
10.1016/j.jallcom.2025.184709
Version
Publisher's PDF
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Volume
1045
Comments
The research is supported by ONR under grant N00014-23-1-2758. The microstructural characterization was performed at the Analytical Instrumentation Facility (AIF) at North Carolina State University, which is supported by the State of North Carolina and the National Science Foundation (award number ECCS-2025064) .