Studies of iron exposed to heavy ion implantation using positron annihilation spectroscopy

• Clusters of about 15–27 vacancies and dislocations are registered.
• Impact of dose on the vacancy clusters size and concentration is observed.
• Probably the long-range effect is observed by positron annihilation method.

Variable energy positron beam and positron lifetime spectroscopy were used to study pure iron exposed to irradiation with 167 MeV Xe26+ heavy ions with different doses of 1012, 1013, 5×1013, 1014 ions/cm2. The positron lifetime spectroscopy revealed the presence of large cluster of about 15–27 vacancies and dislocations. The dislocations are distributed at the depth of about 18 μm i.e. almost twice deeper than the ion implantation range from the surface exposed to the heavy ions implantation. Possible explanation is the long-range effect attributed to the ion implantation into materials.