Defects in the Compound Bi2Te3 caused by Irradiation with Protons

Single-crystal foils of the compound Bi2Te3 were irradiated with 7.5-MeV protons at two levels of flux to the same integrated dose of 5.5×1018 protons/cm2. The specimens were examined by transmission electron microscopy. After irradiation with a flux of 1.8×1013 protons/cm2·sec, clusters of point defects ranging in size from approximately 50 to 250 Å were observed. These clusters annealed out during examination in the electron microscope. After irradiation with a flux of 3.0×1013 protons/cm2·sec, clusters of interstitial atoms and clusters of vacancies could be distinguished. Hexagonal areas were observed after irradiation with the higher flux. Irradiation also promoted the rearrangement of dislocations. Segments of dislocations intersected the surface of the specimens, and some dislocations acquired a jagged appearance.