What is homogeneous nucleation?

Lens adapted to this topic: Competing microscopic pathways

The core definition is not seriously disputed, but researchers challenge the idea that every homogeneous nucleation event follows the simple classical picture of a single, well-defined critical cluster. Simulations and experiments report multistage pathways, metastable intermediates, precritical structures, and nucleation-rate behavior that can depart substantially from classical predictions.

• In some systems, precritical nuclei can have a structure different from that of the later growing nucleus, consistent with Ostwald-like stepwise pathways.
• Experimental studies have reported nucleation-rate dependence on supersaturation that classical nucleation theory does not correctly predict.
• Some researchers argue that the classical critical nucleus is chiefly a conceptual transition-state construct, with dynamics of pre-nucleation clusters providing an alternative description.
• Multistage nucleation through intermediate metastable states is reported across many phase transitions and cannot always be represented by the simplest classical framework.

Featured sourceThe dependence of homogeneous nucleation rate on supersaturationexa.ai4 sourcesView sources