Variable temperature 127I MAS NMR of βAgI. Sensitivity of the 127I MAS linewidth to Ag+ diffusion
Abstract Variable temperature 127 I MAS NMR of βAgI powder, measured from 123 to 413 K is sensitive to Ag + diffusion through the iodine lattice. In low temperature spectra, the iodine ions appear to be in nearly static environments in agreement with the low temperature crystal structure. However, at higher temperatures, substantial broadening of the central transition occurs along with the disappearance of spinning sidebands. The temperature dependence of the central transition linewidth is consistent with the presence of two types of Ag + diffusion with activation energies of 0.17 and 0.0080 eV.