CORRELATION FACTOR OF IMPURITY DIFFUSION IN DIAMOND LATTICE

The correlation factor of impurity diffusion in diamond lattice is reexamined for the general case where the vacancy-impurity binding gives rise to different jump frequencies in different directions for a vacancy at the second coordination sites. Manning's expression is disputed. A formal derivation of an expression is given for the special case where the jump frequency of the vacancy at the second coordination sites is independent of its jump direction, which result is then identical with the expression given by Manning. The correlation factor for the general case is not obtainable analytically, and is computed numerically for an assumed model of vacancy-impurity binding. An expression for an upper limit of the correlation factor in the general case with a positive binding energy is also given and discussed, which becomes a lower limit for the case with a negative binding energy. These results are then compared with Manning's general expression. © 1969 The American Physical Society.