Abstract:Sm2Fe17 alloy as the precursor of a potential permanent magnet (Sm2Fe17Nx) has been paid attention to, but the pure one obtained has been still very difficult until now due to having a distinct difference of melting point between the Fe and Sm metals as raw materials, it impairs seriously the magnetic performance of Sm2Fe17Nx. In this work, this problem was resolved successfully using a method of molten salt electrolysis. A chronopotentiometry was used at 1160℃ to obtain different thicknesses (17.22 ~ 40.34 μm) of single-phase Sm2Fe17 alloy as the product on the iron cathode in LiF-CaF2-SmF3, simultaneous a cyclic voltammetry and a square wave voltammetry were carried out to reveal the electrochemical behavior of Sm3+. The result shows that the reduction of Sm3+ to Sm0 on the iron electrode included two steps. Firstly, a soluble-soluble reaction appears at -0.33 V vs. Cr/Cr2O3 corresponds to the electroreduction of Sm3+ to Sm2+. Secondly, results of CV that Sm2+ can be reduced at -0.78 V vs. Cr/Cr2O3 on the iron electrode in LiF-CaF2-SmF3 melts due to lower activity of metallic samarium in the Sm2Fe17 alloy than that of samarium metal and makes samarium in Sm-Fe alloy more stable.