Melting behavior of nanosized particles embedded in an Al-rich metallic glass

Al87Y7Fe5Pb1 and Al87Y7Fe5In1 alloys have been synthesized via rapid solidification. The microstructure of Al87Y7Fe5Pb1 consists of spherical Pb nanocrystals dispersed within an Al–Y–Fe glassy matrix, whereas Al87Y7Fe5In1 shows non-crystalline In-rich regions. Subsequent isothermal treatments lead to the development of spherical In crystals smaller than 5 nm. Calorimetric investigations indicate for both Pb and In nanocrystalline inclusions a decrease of the melting temperatures compared to that of the respective bulk material, especially the In nanoparticles start melting at about room temperature. The change in the melting behavior is discussed with respect to the size dependence of melting and concerning the details of the interface between the crystalline particles and the amorphous matrix.