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 (r(NW)= 7-30 nm) via differential scanning calorimetry (DSC). Two sequential DSC measurements showed a 1/r(NW) dependency of the melting temperature depression; the first melting temperature decreased from 502 to 486 K with 1/r(NW) whereas the second one was more depressed between 0.8 and 5 K. The melting temperature difference between the first and second cycles increased linearly with 1/r(NW). 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. (C) 2007 American Institute of Physics.