Interstitial solute trapping by edge dislocations

Interstitial solute trapping in the stress field of edge dislocations is considered when solute atoms interact among each other. The Fermi-Dirac statistics are used to account for the short-ranged repulsive interactions which prevents dual site occupancy. The elastic interaction between solute atoms is described in terms of a mean-field attaction plus a macroscopic interaction mediated by the coherency stress field associated with the nonuniform solute distribution. The enhancement of hydrogen solubility in Pd and α-Fe due to trapping in the strain field of edge dislocations is evaluated and compared with experimental results.