The Melting Temperature of Thin Lead Films

Shape, Structural, and Energetic Effects on the Cohesive Energy and Melting Point of Nanocrystals

“…Furthermore, the smaller effect of the wall material for the case of Pb/Al than that for Pb/Ge can also be well understood when we look through Figure b in which it can be easily seen that, with increasing the film’s thickness, the experimental data of Pb films of the Pb/Al system have more tendency toward the bulk melting point than that of the Pb/Ge system. This point has also been mentioned in ref . The experimental data related to the other wall materials are closer to those of the system of Pb/Al.…”

“… T mf ( H ) variation of lead nanofilms. The present model (eqs and with X = 1/ H ) is compared to the LDM and Jiang et al – and (a) to the MD results of ref and (b) to the experimental data of thin Pb films constrained by different kinds of materials (Ge, MgF 2 , Al, Cu, Cr, and Mn). The experimental data plotted in panel b are taken from ref by dividing the therein reported data of melting point depressions (Δ T m = T mb − T mf ) by the value of T mb = 600.61 K. Other required parameters are as those of Figure .…”

“…Tsuboi et al measured the melting points of Pb thin films, consisting of grains, with thicknesses ranging from 10 to 200 nm, confined between different kinds of wall materials (Ge, MgF 2 , Cu, Cr, Al, and Mn), by means of differential scanning calorimetry (DSC). They have found that melting began at the grain boundaries of Pb films . On the basis of their analysis, the effect of the grain boundaries in lowering the melting point of Pb films can be explained through the term Δ T mg = T mb − T mf = 2 mT mb σ sl /( H mb d g ρ s ), where T mf is the melting point of thin films, m is the atomic weight of Pb, σ sl is its solid/liquid interfacial energy, H mb is its bulk latent heat of fusion (per mole), d g is the diameter of the Pb grains in Pb films, and ρ s is the mass density of solid Pb .…”

“…One of their most important properties is their cohesive energy, which is proportional to their melting point and is a significant coupling parameter for other physical/chemical properties such as the Debye temperature, the diffusion activation energy, the vacancy formation energy, etc . It has been well established through theoretical – and experimental – investigations that the cohesive energy and so the melting point of free-standing nanocrystals decrease with decreases in their sizes.…”

Effect of grain size on the melting point of confined thin aluminum films

“…[2][3][4][5][6][7][8][9][10] For example, it was demonstrated that gold nanoparticles may exhibit a melting point of as low as 500 K for a particle size of about 2 nm, while its bulk counterpart melts at 1337 K. 11 In most cases, the linear dependence between the melting point and reciprocal particle size was observed experimentally for nanowires and thin films. [12][13][14][15][16][17] Also, many theoretical models proposed for nanosystems predict such a relationship. [18][19][20][21][22][23][24][25] It is commonly accepted that melting starts at the crystal surface.…”