One-step synthesis of ThMn₁₂-type Sm_0.8Zr_0.2Fe₁₁SiB_x (x = 0–0.2) ribbon magnets via rapid solidification

ThMn₁₂-type iron-rich rare-earth permanent magnetic materials have garnered significant attention due to their exceptional intrinsic magnetic properties. However, challenges such as the metastable nature of the ThMn₁₂-type phase, excessively small single-domain grain size, and complex fabrication processes have hindered the achievement of high phase purity, uniform microstructure, and desirable extrinsic performance. In this study, we directly synthesized ThMn₁₂-type Sm_0.8Zr_0.2Fe₁₁SiB_x (x = 0–0.2) ribbon magnets via boron doping combined with a one-step rapid solidification method. This approach not only simplifies the fabrication process but also enhances phase stability and achieves a uniform microstructure with high ThMn₁₂-type phase purity. By optimizing the boron content and cooling rate, the resulting magnets exhibit a coercivity (H_c) of 6222 Oe, a remanence (M_r) of 80 emu/g, and a remanence ratio (M_r/M_s) of 0.71. This work demonstrates a streamlined approach to producing high-performance ThMn₁₂-type magnets and provides insights into their practical application potential.