Thin-layer deposition and tracer sectioning techniques were used to study the self-diffusion of 86Rb. The data for temperatures ranging from 404 to 603C could be described by:

D (cm2/s) = 27.3 exp[-34.54(kcal/mol)/RT]

Self-Diffusion of Cesium-134 and Diffusion of Rubidium-86 in Cesium Iodide Single Crystals. S.M.Klotsman, I.P.Polikarpova, A.N.Timofeev: Physica Status Solidi B, 1972, 49[2], 423-30