Novel synthesis of single-crystalline TbCu7-type Sm–Fe powder by low-temperature reduction-diffusion process using molten salt

In this study, molten salt was used as a solvent for calcium (Ca) to let a reduction-diffusion (R-D) reaction occur below the melting point of Ca (1115 K), which is the lower limit temperature of the conventional R-D process. When the R-D reaction is conducted below 923 K with LiCl molten salt, submicron-sized TbCu₇-type Sm–Fe powder is formed. The c/a ratio of the powder estimated by a synchrotron X-ray diffraction pattern is 0.8456, which is consistent with the Sm_0.67Fe_5.667(SmFe_8.5) phase. An electron backscatter diffraction analysis reveals that single-crystalline TbCu₇-type SmFe_8.5 powder was synthesized for the first time.