Melting of Isolated Tin Nanoparticles

Abstract

The melting of isolated neutral tin cluster distributions with mean sizes of about 500 atoms has been investigated in a molecular beam experiment by calorimetrically measuring the clusters' formation energies as a function of their internal temperature. For this purpose the possibility to adjust the temperature of the clusters' internal degrees of freedom by means of the temperature of the cluster source's nozzle was exploited. The melting point of the investigated tin clusters was found to be lowered by 125 K and the latent heat of fusion per atom is reduced by 35% compared to bulk tin. The melting behavior of the isolated tin clusters is discussed with respect to the occurrence of surface premelting.

Size dependence of nanostructures: Impact of bond order deficiency

“…For overheating, z ib c i ÿm > 1 and b < 1. Therefore, the models of RMSD instability, LSN, LNG, surface-phonon instability, and the current [317,318], Sn 10e19 [322], Sn 19e31 [266], Ga þ 39e40 [317], Sn 500 [333], and Sn nanosolid on Si 3 N 4 substrate [289]. The T m deviation of Al þ 50e60 clusters [334] from the predictions indicates that the bond nature alteration of Al is less significant compared to Sn and Ga bonds.…”

A Surface Phase Transition of Supported Gold Nanoparticles

“…One of these points is the existence of surface melting, i.e., a coexistence of a liquid-like layer of atoms at the surface with the solid core material at temperatures below the respective melting point. 6,7 While this effect seems to be very basic, there is still a lack of unambiguous experimental proof regarding the details, in particular for gold nanoparticles.…”

“…One of these points is the existence of surface melting, i.e., a coexistence of a liquid-like layer of atoms at the surface with the solid core material at temperatures below the respective melting point. 6,7 While this effect seems to be very basic, there is still a lack of unambiguous experimental proof regarding the details, in particular for gold nanoparticles.Inasawa et al 8 have tried to investigate the shape transformation of elongated particles on a surface induced by static heating (ex situ) and concluded that a transformation into spheres takes places at temperatures as low as 400°C. A similar, very recent study has shown that nanorods with a large aspect ratio of the axes can be transformed at 200°C into spheres and partial relaxation occurs much earlier (100°C).…”

Influence of interparticle interaction on melting of gold nanoparticles in Au/polytetrafluoroethylene nanocomposites

“…[5][6][7][11][12][13] Experimental evidence of the decrease in T m has been demonstrated by a variety of techniques. 2,[14][15][16][17][18] In addition, the influence of surrounding matrix on T m has been demonstrated, e.g., in our previous work. 19 However, the influence of the interaction between the metal nanoparticles ͑or filling factor of nanocomposite͒ on their melting point is an unstudied problem.…”