Internal cation mobilities in the ternary molten system (Na, K, Cs)Cl

For molten (Na, K, Cs)CI system, the relative differences in the internal c ation mobilities at 1023 K are investigated by the Klemm method and the ele ctric conductivity by a direct current method. From these data and the mola r volumes which are evaluated from those of the pure salts on the assumptio n of additivity, the internal mobilities of the each cation, ie., b(Na), b( K), and b(Cs) have been calculated. This result allows us to conclude that the internal mobilities of each cation become b(Cs) < b(Na) < b(K) at x(Cs) = 0.1, b(Na) < b(Cs) < b(K) at x(Cs) = 0.14 and b(Na) < b(K) < b(Cs) at x( Cs) > 0.6. In addition, the molecular dynamics simulation has been performe d on molten (Na, K, Cs)CL for the various compositions at 1023 K. Then, the self-exchange Velocities (SEVs) of Na+, K+, and Cs+ with reference to Cl- have been calculated. The sequence of the internal mobilities of these cati ons is well reproduced by the corresponding SEVs. (C) 2000 The Electrochemi cal Society. S0013-4651(00)04-057-X. All rights reserved.