The diffusivity of 39K in the eutectic melt, K0.68Na0.32, was measured by means of pulsed field-gradient nuclear magnetic resonance techniques between the melting point (about 260K) and 640K. Within the above temperature ranges, the diffusivities were well-described by a single Arrhenius law:

D (m2/s) = 4.1 x 10-8 exp[-0.079(eV)/kT]

A.Feinauer, G.Majer: Physical Review B, 2001, 64[13], 134302