Melting point depression of tin nanoparticles embedded in a stable alpha-alumina matrix fabricated by ball milling

Abstract Ball milling of SnO 2 and Al powders creates Sn nanoparticles embedded in a stable α-Al 2 O 3 phase through a displacement reaction. The production of stable α-Al 2 O 3 phase indicates that sufficient thermal energy was supplied by ball milling to activate the displacement reaction. Melting points of Sn nanoparticles were observed to decrease with reducing particle size. The interfacial energy of solid tin particle-matrix was computed to be larger than liquid tin particle-matrix one. This is due to the formation of incoherent Sn-Al 2 O 3 interfaces by ball milling.