Size-dependent thermal instability and melting behavior of Sn nanowires

Thermal instability and melting behavior of tin nanowires were studied with a decrease of wire radius(rNW=7–30nm) via differential scanning calorimetry (DSC). Two sequential DSC measurements showed a 1∕rNW dependency of the melting temperature depression; the first melting temperature decreased from 502to486K with 1∕rNW whereas the second one was more depressed between 0.8 and 5K. The melting temperature difference between the first and second cycles increased linearly with 1∕rNW. This variation was attributed to fragmentation of nanowires due to Rayleigh instability. Here, fragmentation of long nanowires was suppressed by a template confinement, resulting in the formation of short nanorods.