Nanoscale lead-cadmium alloy inclusions with a nominal composition of Pb:Cd of 1:3 have been made in silicon by sequential ion implantation and subsequent analysis by transmission electron microscopy (TEM) and Rutherford backscattering/channeling analysis (RBS). To ensure crystallinity of the silicon matrix the implantations were carried out at 600 degreesC. This is well above the melting point of both lead and cadmium, and the inclusions were therefore liquid during their formation and growth. The overall shape of the inclusions is cuboctahedral and they have a two-phase microstructure consisting of nearly pure segments of lead and cadmium attached along an internal planar interface. The lead segments grow in parallel cube alignment with the silicon matrix while the orientation of the cadmium segments varies. Due to shrinkage of the inclusions during cooling and solidification in the rigid silicon matrix, the alloy inclusions also contain voids. They appear to be faceted and to have a well-defined location with respect to the inclusion/matrix interface, and in this respect the voids can be considered as a third "phase". During in-situ heating and cooling experiments with TEM and RES analysis, the melting and solidification of the inclusions can be followed directly. The inclusions melt in a two-stage process where eutectic melting is followed by melting of the excess cadmium. This is accompanied by shrinkage of the voids, which eventually disappear around 675 degreesC. Upon cooling the voids reappear while the inclusions are still liquid, and solidification of the inclusions takes place in a process that is reversed in comparison with melting.