Molar volume variation and ionic conduction in molten SmCl3-NaCl, SmCl3-KCl and SmCl3-CaCl2 systems

Molar volume, V-m, and electrical conductivity, kappa, of molten SmCl3-NaCl, SmCl3-KCl and SmCl3-CaCl2 systems were measured by dilatometry and a conventional a.c. technique, respectively. The molar conductivities (Lambda) were evaluated using the data of molar volume and conductivity. The ii values of molten mixtures of SmCl3 with NaCl, KCl or CaCl2 suggested that the existence of dimeric or more polymeric complex anions might be presumed in the melt as was the case in a series of molten rare earth chlorides. Additionally, the Lambda values of molten rare earth chlorides appeared to be affected qualitatively by the cationic radii and the types of linkage, that is, corner-or edge-sharing of octahedral units in melts. The Lambda values of molten SmCl3-NaCl and SmCl3-KCl systems increased with decreasing SmCl3 concentration, x, and in the range of x>0.25 the increment in Lambda to x was much smaller than that in the range of x<0.25. As for molten SmCl2-CaCl2 system, the Lambda values increased almost linearly with decreasing SmCl3 concentration all over the range. (C) 1997 Elsevier Science S.A.