Internal Cation Mobilities in the Molten Binary Systems (Y, La)CI3 and (Y, Dy)C13

Internal cation mobility ratios in the molten systems (Y, La)C13 and (Y, Dy)C13 have been measured at 1073 K by the Klemm method and the electrical conductivities of these systems have been measured by conventional ac techniques. From these studies and the data available on the densities of the pure melts, the internal mobilities, u, have been calcu-lated; uLa is greater than zt, while the ionic radius of La3 is greater than that of Y3'. On the other hand, u is slightly greater than u07, where the ionic radii are much the same and the mass of Y3 ' is much less than that of Dy3'. Internal mobil-ities of all the cations in both (Y, La)C13 and (Y, Dy)C13 systems decrease with increasing molar volume of the mixtures. The dominant electrically conducting cationic species are conjectured to be the nonassociated rare-earth cations