A molecular dynamics simulation of the electric and thermodynamic properties in molten (Nd-1/3, Na or K)Cl mixtures

Molecular dynamics simulations have been carried out on molten (Nd-1/3, K)C l at 1065 and 1073 K and (Nd-1/3, Na)Cl at 1124 K for various compositions. The calculated self-exchange velocity (upsilon), self-diffusion coefficien t (D), electrical conductivity (K) and enthalpy of mixing (DeltaH(mix)) wer e compared with the corresponding experimental values. The calculated resul ts revealed that upsilon and D of potassium decrease with increasing anmoun t of neodymium, as expected from the experimental internal mobility (b). Th e decrease of b(K), upsilon (K), and D-K are attributed to the tranquilizat ion effect by Nd3+ which strongly interacts with Cl- as well as Dy3+. On th e contrary, b(Nd), upsilon (Nd), and D-Nd increase with increasing concentr ation of Nd3+. This might be ascribed to the stronger association of Nd3+ w ith Cl- due to the enhanced charge asymmetry of the two cations neighboring Cl-. In addition, the sequences of the calculated upsilon 's, D's and K's for the various compositions were consistent with those of the known experi mental results. The experimental enthalpy of mixing with its negative depen dence on the cation size was qualitatively reproduced.