Fasendringen

Fasendringen is a term occasionally used in Scandinavian contexts to denote a phase change of a material or system as external conditions such as temperature, pressure, or composition vary. In Norwegian and Danish, the more common terms are faseendring or faseovergang; in Swedish, corresponding terms are fasomvandling or fasövergång. The exact form fasendringen is not standard in most technical literature, and English-language texts typically use phase transition or phase change.

Phase transitions can be either first-order, which involve latent heat and discontinuous changes in properties, or second-order (continuous) with no latent heat but diverging susceptibilities. They are described using thermodynamics, statistical mechanics, and order parameters. Phase diagrams show which phase is stable under given temperature and pressure.

Common examples include solid–liquid transitions (melting/freezing), liquid–gas transitions (vaporization/condensation), and solid–solid transitions such as polymorph changes. Magnetic and superconducting transitions are other important classes, where symmetry changes characterize the transition.

Kinetics of fasendringen involve nucleation and growth or spinodal decomposition, and can exhibit hysteresis and supercooling. In practical contexts, phase changes affect material properties such as strength, conductivity, and hardness, and are central to processes like alloy design, crystallization, and cryogenics.

See also: phase transition; phase diagram; latent heat; nucleation; critical point.