Synthesis and characterization of Sm2Co17 using electrodeposition and reduction-diffusion process

• Published in: Journal of alloys and compounds 2022-04, Vol.901, p.163669, Article 163669
• Main Authors: Park, JungHo, Kwon, HyunJun, Park, Jong-Hwan, Ro, Jae Chul, Suh, Su-Jeong
• Format: Article
• Language: English
• Subjects: Amorphous alloys; Aqueous media; Aqueous solutions; Coercivity; Electrodeposition; Glycine; High temperature; Magnetic materials; Magnetic properties; Magnetic property; Magnetic saturation; Magnetometers; Permanent magnet; Phase transitions; Reducing agents; Reduction-diffusion process; Samarium; Samarium base alloys; Samarium cobalt
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.163669

•Combination of electrodeposition in an aqueous medium and a reduction-diffusion process used.•Sm2Co17 magnetic material synthesized by this combined process.•Morphology, phase transformation, and magnetic properties investigated.•R-D process carried out at 800 ℃, which was lower than the conventional temperature.•Mechanism of Sm2Co17 formation during the R-D process explained. Sm2Co17 magnetic materials were synthesized using a combination of electrodeposition from an aqueous medium and a reduction-diffusion (R-D) process. The electrodeposition solution contained a complex agent (glycine) because of a significant reduction potential difference between Sm and Co. Co, Sm, O, and S were incorporated in the as-deposited Sm-Co alloy. The Sm compounds with O and S were difficult to reduce to metallic Sm without a reducing agent at high temperatures (>1000 ℃). Thus, a mixed sample of the as-deposited Sm-Co alloy, Ca granules, and NaCl was converted into Sm2Co17 at 800 ℃ during the R-D process. The annealing time was varied from 3 h to 12 h. X-ray diffraction analysis showed that the as-deposited Sm-Co alloy was amorphous. After the R-D process, the Sm-Co alloy was converted into a crystalline Sm2Co17 form. An increase in the Sm2Co17 phase transformation was observed in the morphology analysis of the cross-section. Based on these analyses, the mechanism involved in the formation of Sm2Co17 was elucidated. The changes in the magnetic properties, including saturation magnetization (Ms) and coercivity (Hci), were determined using a vibrating sample magnetometer.