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Transient electrochemical techniques show that in NaCI-KCI melts the reduction of TiCI4 occurs through a three-step reaction, Ti(IV) --~ Ti(III) --> Ti(II) --~ Ti. The diffusion coefficients of the electroactive species and the standard potentials, E~%, E3%, and E2~ for the couples, Ti(IV)/Ti(III), Ti(III)/Ti(II), and Ti(II)/Ti were measured by chronopotentiometry and cyclic voltammetry. The influence of the melt composition has been examined. The addition of fluoride ions, a common ligand for titanium ions, induces a negative shift of about 1 Vin the potentials, E~3 and E~2. It results in a decreasing influence of the disproportionation process 3Ti(II) --~ Ti + 2Ti(III) which depends on the F/Ti ratio and on the concentration of titanium ions.

The thermodynamic properties of Ni−Pt metallic alloys, in the temperature range 500−720 °C, are measured from energy dispersive analysis of the X-ray of alloys prepared by fused salt electrolysis at constant potentials in the cell:  Ni−Pt alloy|fused electrolyte + NiCl2|Ni. For nickel-rich alloys, the partial entropy of nickel exhibits a nearly ideal behavior. For a molar fraction of nickel between 0.4 and 0.6, a rapid change in the thermodynamic properties occurs. A minimum in the entropy of mixing is found at xNi ≃ 0.5. The departure from ideality of the Gibbs energy is mainly due to the negative value of the molar enthalpy of mixing; ΔH 0.5 = −10.5 kJ mol-1. This behavior, which results from the preferential interaction Pt−Ni, is linked to an order−disorder transformation around the equiatomic composition.