Electrochemical formation of erbium-aluminum alloys from erbia in the chloride melts

This work presents an electrochemical study of Er3+ and Al3+ in the LiCl-KCl-AlCl3-Er2O3 melts at 773 K. Gibbs energy calculation shows that AlCl3 can favorably chloridize Er2O3 and release Er3+ ions under this condition. Cyclic voltammetry, square wave voltammetry, chronopotentiometry and open-circuit chronopotentiometry were applied using a molybdenum electrode to investigate the reduction behavior of Er3+ and Al3+ and to identify the Er-Al alloys. A series of redox signals corresponding to different kinds of Er-Al alloys were revealed. Potentiostatic and gavanostastic electrolysis were both conducted on an aluminium electrode to prepare the Er-Al alloys. The obtained deposits were charaterized by SEM-EDS and XRD. A layer of ErAl3 was obtained by potentiostatic electrolysis, whereas two kinds of intermetallic compounds of ErAl3 and ErAl2 were formed by galvanostatic electrolysis.