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

Thermodynamic and electrochemical properties of holmium and HoxAly intermetallic compounds in the LiCl-KCl eutectic

“…Except for the redox couples A/A' and C/C' corresponding to the formation and dissolution of the holmium and aluminum metal, a series of cathodic signals (D, F and G) and their corresponding anodic peaks (D', F', G' and G") can be also observed due to the depolarization of the electrode and deposition of Ho(III) on the previous formed aluminum metal to form Al y Ho x intermetallic compounds and the dissolution of Ho from these Al y Ho x intermetallic compounds, respectively. Similar phenomena were also observed in our previous works about Er [28], Ce [36] and Dy [37] intermetallic compounds.…”

“…In addition, the reason of other absent Ho-rich phases in our experiments could be due to the fast transformation of one phase into another since the aluminum plate can act as a good media for the diffusion of Ho into the Al bulk at high temperatures. Similar phenomena were also observed in our previous works for preparing Al y Sm x , Al y Er x and Al y Th x intermetallic compounds [15,27,28]. In Fig13(a to f), the morphology about the surface and intersecting surface of the corresponding deposits are characterized by SEM image.…”

“…(22). However, similar to the co-reduction behaviors of Er(III) [28] and Sm(III) [27] with Al(III) in the melts, the presence of these plateaus depends on the concentrations of target ions in the melts and also the electrodeposition time in OCP tests due to the lower inhomogeneous transformation rate of some intermetallic compounds. So it cannot be easy to figure out the emf of some plateaus which exhibit only limited information and slight variation on the OCP curves.…”

“…Furthermore, Castrillejo et al [22][23][24][25][26] have studied the preparation of Al-Ln intermetallic compounds on the aluminium cathode. Moreover, in our previous works, deposition of Ln-Al alloys at more cathodic potential was also achieved [27,28].…”

“…According to thermodynamic analysis [29], the Gibbs energy (DG) of this reaction is calculated to be -309.9 kJ mol À1 at 773 K. The same melts preparation process has been introduced in our previous paper [15,28]. The initial concentrations of Ho(III) and Al (III) in the bath were determined by using an inductively coupled plasma atomic emission spectrometer (ICP-AES, Perkin Elemer NEXION 300D).…”