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 RD 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 Sm0.67Fe5.667(SmFe8.5) phase. An electron backscatter diffraction analysis reveals that single-crystalline TbCu7-type SmFe8.5 powder was synthesized for the first time. (C) 2021 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.

Automated summary

In this study, molten salt was used as a solvent to enable a reduction-diffusion reaction of calcium below its melting point. When the reaction was carried out with LiCl molten salt below 923K, submicron-sized TbCu7-type Sm-Fe powder was synthesized, and for the first time, single-crystalline TbCu7-type SmFe8.5 powder was also obtained.