Compound formation in lanthanide–alkali metal halide systems

Abstract

The phase diagrams of trivalent lanthanide-alkali metal halide systems range from simple eutectic systems to systems with one or several congruently or incongruently melting compounds. Using both literature information and the authors' extensive experimental results, the LnX 3 -MX binary mixture phase diagrams were screened in terms of the IP Mz /IP Ln3z ratio (IP i : z i /r i ; z i : ionic charge; r i : ionic radius; Ln: lanthanide, X: halide and M: alkali metal). A similar approach was conducted on the divalent LnX 2 -MX lanthanide-alkali metal halide phase diagrams ranging from simple eutectic to one or more congruently melting compounds. Lanthanides being widely used as simulants of actinides, this classification can constitute a useful predictive tool for those still unexplored systems.

In Situ Electrochemical Study of the Coexistence of Eu3+ and Eu2+ in Molten LiCl-KCl by Rotating Disc Electrode

“…In addition, the diffusion coefficients of Eu 3+ and Eu 2+ are not the same. It has been reported that K 3 EuCl 6 is formed when EuCl 3 is added into KCl and K 2 EuCl 4 is formed with the addition of EuCl 2 to KCl, 29 which might cause the difference between the measured D Eu3+ and D Eu2+ .…”

Thermodynamic Assessment of CrCl2 with NaCl–KCl–MgCl2–UCl3–UCl4 for Molten Chloride Reactor Corrosion Modeling

“…We identified likely solid solutions in the system from cationic potential trends as described by Gaune-Escard et al The methodology allows the number and type of phases in salt mixtures to be estimated based on correlation with the cationic potential ratio for each experimentally known system involving CrCl 2 (Table ). The ratio is defined by eq : normalI normalP normalA normalI normalP Cr = z normalA / r normalA z Cr / r Cr where z is the cation charge and r is the 6-coordinated Shannon ionic radius .…”