Abstract
The solution strengthening of sodium and potassium halide crystals by dissolved alkaline earth atoms is accounted for quantitatively. Strengthening is associated with the change in electrostatic energy that occurs when a divalent ion‐vacancy complex is sheared by a dislocation that passes through it. The model yields a hardening coefficient of 11 × 109 dyn/cm2 compared with the experimental value of 9.2 × 109 dyn/cm2.