Self-organized Cu-Ag nanocomposites synthesized by intermediate temperature ion-beam mixing

We perform an investigation of ion-beam mixing in the immiscible system Ag- Cu based on cross-sectional transmission electron microscopy. Multilayered samples consisting of ten periods of (6.7 nm Cu/11.2 nm Ag) are irradiated at temperatures ranging from 25 to 225 degreesC with normally incident 1 Me V Kr ions to doses in the range 1-2x10(16) ion/cm(2), enough to reach a non equilibrium dynamical steady state. Regardless of the irradiation temperatu re, extensive grain growth takes place. At intermediate temperatures, compe tition between thermal decomposition and irradiation mixing results in a na nometer-scale phase separation. This spontaneous decomposition demonstrates that ion-beam mixing can be used as a processing tool to synthesize nanoco mposite materials. (C) 2001 American Institute of Physics.