Experimental Confirmation of the Kawasaki-Einstein-Stokes Formula; Measurement of Small Correlation Lengths

The Kawasaki formula D=kT6πηξ is experimentally verified using the measured values in a cyclohexane-aniline critical mixture near Tc. Its application in a wide range of temperatures above Tc, where the viscosity is known, is completely verified by the measurements of the diffusion coefficient D and allows a direct determination of the correlation length ξ in a domain where no other optical method is suitable. We show that the power law ξ=ξ(ε)^ν is followed up to 40^∘{} from Tc.