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

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 (M_s) and coercivity (H_ci), were determined using a vibrating sample magnetometer.