Nucleation and growth behavior of Cu-Al precipitates in He implanted and annealed aluminum

The effects of He on the thermal evolution of Cu-Al precipitates produced a fter Cu+ and He+ implantation into pure Al foils were analyzed as a functio n of the implanted He fluence and post-implantation thermal annealing tempe rature. The profiles of Cu and He were measured via Rutherford backscatteri ng (RBS) and elastic recoil detection analysis (ERDA) techniques, The preci pitate and bubble morphology were investigated by transmission electron mic roscopy (TEM). In comparison to a sample implanted only with Cu+, we observ e that the presence of He leads to larger Cu-Al precipitates upon low-tempe rature annealing. For high-temperature annealing the situation is opposite, This behavior is discussed considering precipitate nucleation and growth p rocesses affected by the reduction in the vacancy field due to the formatio n of He bubbles, (C) 2001 Elsevier Science B.V, All rights reserved.