One-dimensional NMR images of the 19F concentrations were recorded as functions of time during the intercalation of AsF5 into highly oriented pyrolytic graphite at room temperature. The image maintained a constant shape at all times during intercalation, indicating the absence of AsF5 concentration gradient in the radial direction. The NMR gradient diffusion technique was used to determine the macroscopic 19F diffusion coefficient for stage-I highly oriented pyrolytic graphite/AsF5 at room temperature; the result was D = 4 x 10-6cm2/s.

Graphite-AsF5 Intercalation Kinetics and Diffusion by NMR Imaging. Chingas, G.C., Milliken, J., Resing, H.A., Tsang, T.: Synthetic Metals, 1985, 12[1-2], 131-6