Strain-rate cycling tests were carried out, during simultaneous Blaha-effect measurements, on Br--doped single crystals. Plots of the strain-rate sensitivity of the flow stress, versus the stress decrement due to the superposition of an oscillatory stress, were studied. It was found that the curves were stair-like, exhibited plateau regions at low and high stress decrements, and an intermediate region where the strain-rate sensitivity decreased with increasing stress decrement; as already found for Br--doped KCl. The stress at the first bending point of the curve, which was considered to be the effective stress due to Br-, decreased with increasing temperature and became zero at a critical temperature of 270K. The difference between the strain-rate sensitivities at the first and second plateau regions decreased with temperature; contrary to the case of Br--doped KCl. This implied that the force-distance profile of the interaction between a dislocation and a Br- ion in Br--doped NaCl was different to that in Br--doped KCl and was pointed near to the top. It was found that the interaction energy between a dislocation and a Br- impurity in NaCl was 0.37eV.

Investigation of Interaction between a Dislocation and a Br- Ion in NaCl:Br- Single Crystals. T.Ohgaku, H.Teraji: Physica Status Solidi A, 2001, 187[2], 407-13