Ionic conduction mechanism analysis for neodymium complex in phosphonium ionic liquids and potassium bis (trifluoromethyl-sulfonyl) amide melts

It is important to investigate the ionic conduction mechanism for neodymium complex; Nd(III) in ionic liquids and low-temperature molten salts. The temperature dependence of ionic conductivities in [P-2225][TFSA] dissolving 0.05-0.50 M Nd(III) was evaluated from Vogel-Fulcher-Tammann (VFT) equation in this study. The concentration dependence of ionic conductivities for Nd(III) in [P-2225][TFSA] was evaluated from Kohlrausch law. Considering from Walden plot, this result indicated that the ionic conduction was attributed to the transfer of [P-2225](+) and Nd3+ cations, and [TFSA](-) anions even in the presence of Nd(III). Moreover, The VFT parameters of the ionic conductivities in [Nd-1/3,K][TFSA] melts with molar fraction of Nd; x(Nd)=0.010-0.075 were also estimated in this study. Furthermore, the self-diffusion coefficients of cation and anion in [P-2225][TFSA] were calculated from molecular dynamics simulation. This tendency of diffusivity for each ion was consistent with the ionic conductivity.