We induced Co to form inclusions in Ag by ion implantation of Co into
Ag and by coevaporation of both elements in a MBE system.
Mössbauer spectroscopy at 4.2 K reveals the hyperfine
fields present in the bulk and at the interface of the
precipitates. By post-implanting the 57Co
activity into the coevaporated samples, we strongly
enhanced this interface population, which facilitates
the determination of the associated magnetic hyperfine
field. The dependence of the precipitate size on the Co
concentration and annealing treatment is monitored. We
propose a simple model which allows to estimate the
precipitate size in the case of preferential interface
population