Crystallization

Crystallization is the formation of a crystal from a disordered phase as particles organize into long-range order. It can occur from a melt, solution, vapor, or amorphous solid.

Nucleation: The initial formation of a stable nucleus of a new phase within a parent phase. Crystallization begins when an ordered cluster becomes stable enough to grow.
Crystal structure: The periodic arrangement of atoms, ions, or molecules in a crystalline solid. Crystallization produces this repeating arrangement from a disordered starting phase.
Recrystallization: A purification technique that dissolves a solid and then crystallizes it from solution. It uses controlled crystallization to separate a desired compound from impurities.
Vitrification: The formation of an amorphous solid by cooling a liquid without crystallizing it. Rapid cooling can suppress crystallization and preserve disorder instead.
Crystal growth: The enlargement of a crystal as particles attach to its surface in an ordered arrangement. After nucleation, growth extends the crystal lattice into surrounding material.
Crystal lattice: An idealized periodic array of points representing the repeating structure of a crystal. It provides the geometric framework that particles adopt as order develops.
Fractional crystallization: A separation process that crystallizes components of a mixture at different conditions or stages. Differences in solubility let crystallization separate substances in mixtures.
Glass transition: The temperature-dependent change between a glassy amorphous state and a more mobile supercooled liquid. It governs the mobility of disordered materials that might otherwise crystallize.
Supersaturation: A state in which a solution contains more dissolved material than its equilibrium solubility permits. It supplies the thermodynamic driving force for nucleation and growth from solution.
Amorphous solid: A solid whose particles lack the long-range periodic order characteristic of crystals. It is a disordered solid state from which crystallization can occur.

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