Insight into the premelting and melting processes of metal nanoparticles through capacitance measurements

We demonstrate that capacitance measurements on metallic nanosystems (specifically Ga nanoparticles embedded in dielectric matrix) yield information to clarify the complex phenomenon of melting, where different mechanisms may interplay. The technique is proved to be extremely powerful to study the role of surfaces and interfaces on a twofold basis: very short (of the order of a few angstroms) penetration depth of the probing electric field and a strict relationship of capacity with entropy. We show that initial disorder starts to take place approximate to65 degreesC before full melting, with evidence of two regimes in the premelting and melting region.