Abstract
Sn-3.5Ag-0.5Cu nanoparticles were synthesized by chemical precipitation with NaBH 4 . By using x-ray diffraction and transmission and scanning electron microscopy, the microstructural characteristics of particle growth were evaluated. The results indicated that the primary particles after precipitation were (Ag,Cu) 4 Sn, with a size of 4.9 nm. (Ag,Cu) 4 Sn was transformed into (Ag,Cu) 3 Sn, when the total amount of Sn contributed from both (Ag,Cu) 4 Sn and Sn covering the (Ag,Cu) 4 Sn overtook that of (Ag,Cu) 3 Sn. The final particle size of polycrystalline particles was 42.1 nm owing to the depletion of Sn atoms in the solution. Nucleation and growth mechanisms of Sn-3.5Ag-0.5Cu nanoparticles are also discussed and proposed.