Dislocation-Point Defects-Induced by X-Irradiation Interaction in Alkali Halide Crystals

Strain-rate cycling tests under superposition of ultrasonic oscillation were carried out at 77–293 K for two kinds of samples: non-irradiated and X-ray-irradiated KBr single crystals. Point defects induced by X-ray irradiation have weak interaction with dislocation and act as obstacles to dislocation motion. Assuming that the defect is tetragonal, the interaction energy for the break-away of a dislocation from the defect has been obtained by fitting the Barnett model to experimental results. Then, the value of interaction energy was determined to be 0.81 eV for the crystal. This result is compared with it in other crystals (NaCl, NaBr, and KCl) by the X-irradiation.