nucleuates

Nucleates refers to the initial stable arrangement of atoms or molecules that triggers the formation of a new thermodynamic phase within a supersaturated or supercooled medium. This process is known as nucleation, and nucleates are the seeds for this transformation. Without nucleates, a substance might remain in a metastable state indefinitely, even when conditions are favorable for a phase change.

There are two primary types of nucleation: homogeneous and heterogeneous. Homogeneous nucleation occurs spontaneously within a pure substance when its molecules randomly assemble into a stable cluster exceeding a critical size. This requires significant energy input and is less common in practical scenarios. Heterogeneous nucleation, conversely, occurs on the surface of foreign particles, impurities, or structural defects within the medium. These surfaces provide a lower energy pathway for the formation of nucleates, making this type of nucleation far more prevalent. Examples include the formation of ice crystals on dust particles in clouds or the crystallization of sugar from a solution containing impurities. The presence and nature of these nucleating agents significantly influence the rate and characteristics of the phase transition.