A molecular dynamics simulation of the transport properties of molten (La1/3,K)Cl

Molecular dynamics simulations of molten (La1/3,K)Cl at 1123 K have been performed in order to investigate the correlation between simulated dynamical properties such as the self-exchange velocity (ν), the self-diffusion coefficient (D) and the electrical conductivity (κ) and the corresponding experimental values. The simulated results revealed that ν and D of potassium decrease with increasing mole fraction of lanthanum, as expected from the experimental internal cation mobilities, b. The decrease of bK, νK and DK is ascribed to the tranquilization effect by La3+, which strongly interacts with Cl-. In contrast, bLa, νLa, and DLa increase with increasing concentration of La3+. The distorted linkage of the network structure of [LaCl6]3- units was disconnected with increasing the concentration of the alkali chloride. This might be attributed to the stronger association of La3+ with Cl- due to the enhanced charge asymmetry of the two cations neighboring Cl-. The sequence of the calculated ν's, D's, and κ's is consistent with those of the referred experimental results. (orig.)