New synthesis approach for low temperature bimetallic nanoparticles: size and composition controlled Sn-Cu nanoparticles.

A various size of Sn-Cu nanoparticles were synthesized by using a modified polyol process for low temperature electronic devices. Monodispersive Sn-Cu nanoparticles with diameters of 21 nm, 18 nm and 14 nm were synthesized. In addition, the eutectic composition shift was also observed in nano-sized particles as compared with bulk alloys. By controlling the size and eutectic composition, a significant melting temperature depression of 30.3 degrees C was achieved. These melting temperature depression approaches will reduce adverse thermal effects in electronic devices and provide the synthesis guidelines for bimetallic nanoparticles with a low melting temperature.