The Structure and Magnetic Properties of Sm[sub.2]Fe[sub.17]CIx/I Compounds Prepared from Ball-Milled Mixtures of Sm[sub.2]Fe[sub.17] and Carbon Nanotubes or Graphite

• Published in: Metals (Basel ) Vol. 14; no. 4
• Main Authors: Mikheev, Vladislav A, Bordyuzhin, Igor G, Gorshenkov, Mikhail V, Savchenko, Elena S, Dorofievich, Irina V, Shchetinin, Igor V
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.04.2024
• Subjects: Air-turbines; Annealing; Corrosion and anti-corrosives; Graphite; Iron compounds; Magnetic properties; Magnets, Permanent; Nanotubes
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met14040472

The processing route of Sm[sub.2]Fe[sub.17] carbides is shorter than that of nitrides, which can potentially be used for cost-effective mid-performance magnets’ production. The magnetic properties of Sm[sub.2]Fe[sub.17]C[sub.x] compounds can be controlled at the annealing step, which allows them to be used for a variety of applications. In this work, X-ray diffraction (XRD) analysis, Mössbauer spectroscopy, scanning and transmission electron microscopy (SEM, TEM) and vibrating sample magnetometry (VSM) were used for characterization of the structure and magnetic properties of Sm[sub.2]Fe[sub.17]Cx compounds. The powder samples were prepared by high-energy ball milling of Sm[sub.2]Fe[sub.17] mixtures with carbon nanotubes (CNT) or graphite with subsequent annealing. The formation of Sm[sub.2]Fe[sub.17]Cx compounds after annealing was followed by the formation of α-Fe and amorphous Sm[sub.2]O[sub.3]. The hyperfine field values of Fe atoms of all the Sm[sub.2]Fe[sub.17] lattice sites increased by 12% on average after annealing that was caused by carbon diffusion. The coercivity of the samples peaked after annealing at 375 °C. The samples with CNT demonstrated an increase of up to 14% in coercivity and 5% in specific remanence in the range of 250–375 °C annealing temperatures.