Melting behavior of Sn x (SiO 2 ) 100− x granular metal films

Abstract

We have prepared a series of Sn x SiO 2 ) 100− x granular metal films by RF magnetron sputtering with nominal Sn compositions from x = 30 to x = 90 at. %. X-ray diffraction and transmission electron microscopy measurements confirm that these films consist of small Sn particles, ranging from about 10 nm to 200 nm in mean diameter, embedded in an amorphous SiO 2 matrix. These measurements also indicate that the mean Sn particle size decreases and the particle size distribution becomes more narrow as the Sn concentration is reduced. A differential scanning calorimeter has been used to study the size dependence of the melting temperature of the Sn particles. The melting temperature has been found to be increasingly depressed from the bulk value as the Sn particle size decreases. No evidence of an enhancement in the melting temperature at any particle size has been found. The evolution of the melting behavior of each sample with repeated melting and solidification cycles has also been studied.