Published online by Cambridge University Press: 16 February 2011
The damage (disordered zones and vacancy loops) produced in the ordered alloy Ni3AI by irradiation with different ions (Ar+, Kr+, Xe+), ion energies (30 and 50 keV), and at 30 and 300 K has been investigated by using transmission electron microscopy. At room temperature and at constant ion energy, the average size of the disordered zones increases as the ion mass increases from Ar+ to Kr+and to Xe+ ions. This trend is opposite to that of the collisional volume which decreases with increasing ion mass and highlights the importance of the thermal spike in causing disorder. At room temperature and at constant ion mass, the zone size increases with increasing ion energy. At 30K, for the same ion mass and ion energy, the size of the disordered zones is smaller than at room temperature. At both irradiation temperatures, the dislocation loop yield increases with increasing ion energy and ion mass. The loop yield was lower for irradiations at 30K compared to at 300 K. Comparison of the dislocation loop yield and the size of the disordered zones indicates that the probability for forming a loop increases with the size of the disordered zone.