A Note on the Hole Theory of Diffusion

摘要: The activation energy ${Q}_{x}$ for diffusion in a dilute metallic solution cannot be less than the ${Q}_{0}$ self-diffusion, if solute atoms can move only through medium of "holes" which diffuse to them from solvent lattice, displace them, and leave another direction. Since experiments show that generally ${Q}_{x}l{Q}_{0}$ an alternative mechanism is required. Solute are not so firmly bound lattice as will tend trap holes form solute-hole molecules. These molecules units dense by cycles inversion re-orientation. This yields constant value $D={A}^{*} \mathrm{exp} [\ensuremath{-}\frac{(W+S)}{\mathrm{RT}}],$ where $W$ required hole adjacent atom, $S$ re-orientation or molecule. ${Q}_{x}(\ensuremath{\equiv}W+S)$ may much smaller either binding solvent. ${A}^{*}$ should significantly corresponding $A$ self-diffusion. Both these predictions accord with data. same considerations apply also liquids.