Interaction between a dislocation and monovalent anion in various alkali halide crystals

Abstract

It was investigated from (L 0 /L)2 versus φ 0 curve that the Friedel relation between the effective stress and the average length of dislocation segments, L, is appropriate for the interaction between a dislocation and the monovalent anion in various alkali halides single crystals (NaCl: Br ). Here, L 0 represents the average spacing of monovalent anions on a slip plane and φ 0 is the bending angle at which the dislocation breaks away from the anion at the temperature of 0 K. This is because the anions are the weak obstacles such as impede the dislocation at φ 0 above about 150 degrees, where the Friedel relation agrees with the Fleischer one (L 0 2 = L 2 (π-φ 0 )/2). Furthermore, the values of (L/ L 0 ) were found to be within 4.05 to 5.87 for the crystals.