SelfDiffusion Coefficient in Solid Argon
Abstract
Selfdiffusion in argon crystals is discussed on the basis of the mobility of vacancies, and in the scheme of the "absolute rate theory." Detailed calculations are made for the heat of activation Q and for the preexponential factor D_{0} including quantum corrections. The change of potential energy is evaluated first by minimizing the lattice energy with respect to the displacement of the four atoms around the diffusing particle, next by calculating firstorder elastic relaxation of the entire lattice. The change of vibrational properties is evaluated in the Einstein approximation. Including the contributions for the hole formation, the values D_{0}=4.20×10^{4} cm^{2} sec^{1}, Q=13.85×10^{2} ev, are found at T=80°K the zeropoint energy contributes 5% to the heat of activation.
 Publication:

Physical Review
 Pub Date:
 July 1961
 DOI:
 10.1103/PhysRev.123.141
 Bibcode:
 1961PhRv..123..141F