Magnetic "Tagging" of Superionic Conductors

Introducing magnetic ions (e.g., ${\mathrm{Mn}}^{2+}$) into a superionic conductor produces large temperature-dependent effects on the NMR linewidths. This makes possible the determination of the mobile species, hopping times of ${10}^{-3\mathrm{}}$-${10}^{-12\mathrm{}}$ seconds, and the range of ionic motion In magnetically "tagged" Pb${\mathrm{F}}_2$, comparison is made between experiment and theory for the various regions of temperature in which the hopping rate of the ${\mathrm{F}}^{-}$ ions is slow, comparable to, or fast, compared with the ${\mathrm{F}}^{19}$ transferred hyperfine interaction with the ${\mathrm{Mn}}^{2+}$ electronic spin.