Electron spin resonance study of electron localization and dynamics in metal-molten salt solutions: comparison of M-MX and Ln-LnX(3) melts (M = alkali metal, Ln = rare earth metal, X = halogen)

摘要

We have studied the electron spin resonance (ESR) spectra in liquid K-KCl and M-(NaCl/KCl)(eut) mixtures at different concentrations in salt-rich melts approaching the metal-nonmetal transition region. In both systems F-centre-like characteristics are found. Strongly exchange narrowed signals clearly indicate that fast electron exchange occurs on the picosecond timescale. In contrast, the ESR spectra of a (NdCl2)(NdCl3)-(LiCl/KCl)(eut) melt are characterized by a large line width of the order of 10(2) mT which decreases with increasing temperature. In this case, the g-factor and correlation time are consistent with the model of intervalence charge transfer, which is supported by recent conductivity and optical measurements. The different transport mechanisms will be discussed. [References: 38]