Low temperature electron-irradiation ofβ-tin

Abstract High purity polycrystalline wires of β-tin have been irradiated at 5 K by 0.7 to 2.0 MeV electrons. Damage was monitored by electrical resistance measurements taken at 4.2 K From a comparison of energy-dependent damage rate measurements with electron displacement cross section curves based on the calculations of O. S. Oen, a threshold displacement energy of 22 ± 2 eV was found. Isochronal anneals revealed three recovery substages below 12 K, accounting for 63% of the total, followed by rather constant recovery up to 180 K. Irradiation at 16 K indicated free interstitial migration below this temperature. A partial characterization of this stage suggests that the largest major substage (10.5 K) may be due to dose pair interstitial-vacancy annihilation, although a correlated recovery model cannot be ruled out completely.