Thermodynamics of melting and freezing in small particles

• Published in: Surface science 1995-11, Vol.341 (1), p.40-50
• Main Authors: Vanfleet, Richard R., Mochel, J.M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Crystallization; Equilibrium thermodynamics and statistical mechanics; Exact sciences and technology; Freezing; Interfacial energy; Lead; Melting; Metals. Metallurgy; Nucleation; Other nonelectronic properties; Particles (particulate matter); Phase interfaces; Physics; Platinum; Solid surfaces and solid-solid interfaces; Solid-fluid interfaces; Solid-liquid interfaces; Statistical mechanics; Surface energy; Surface melting; Surface stress; Surface tension; Surface thermodynamics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wetting
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(95)00728-8

The properties of small particles can be markedly different from the bulk. A classical thermodynamic treatment of the melting and freezing of small particles, including the effects of surface-induced order, predicts an energy barrier between a surface melted state and the liquid droplet. The requirement of homogeneous nucleation over the barrier on laboratory time scales predicts melting and freezing temperatures that vary from the bulk temperatures and from each other. For very small particles the energy barrier is so small that the melting and freezing temperatures are the same. However, above a few nanometers in radius the melting and freezing temperatures are different. This approach also predicts a low temperature region where a disordered particle would stay disordered for extended periods of time. This model only applies to the situation where the melt wets the solid.