Melting behavior of Pb-Sn alloy nanoparticles

•Xiao-Jun Gu, Peter Bunzel, Harald Rösner, Jörg Weissmüller und Gerhard Wilde
Forschungszentrum Karlsruhe GmbH, Institut für  Nanotechnologie, Postfach 3640, D-76021 Karlsruhe

The melting behavior of finite systems has been of considerable theoretical and experimental interest for many years. In most cases, it has been reported that particles of finite sizes melt at temperatures significantly below their equilibrium melting points. There has also been evidence that superheating rather than melting point depression is achievable for some metallic particles. However, very limited investigations exist on the melting of nano-sized alloys as opposed to elemental solids. In this study, nanoscale Pb-Sn inclusions were synthesized either by infiltration of binary Pb-Sn alloys into arrays of laterally nanostructured porous Al2O3 templates under high pressure or by melt spinning immiscible Al-rich Al-Pb-Sn alloys, respectively. The morphology and partitioning as well as the melting behavior of the nanoscaled Pb-Sn inclusions were studied in dependence of size, nominal composition and processing pathway by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). This project is supported by the DFG within the SPP 1120 (WI 1899/2-1).