Phasesolid

Phasesolid is a term used to denote the solid phase of matter in thermodynamics and materials science. In this phase, a substance preserves a definite shape and volume, unlike liquids which flow and gases which expand to fill their container. Solids typically exhibit high density, low compressibility, and mechanical rigidity, with particle arrangements that can be crystalline or amorphous.

Crystalline solids have long-range order with repeating unit cells forming a lattice; amorphous solids lack this long-range order and behave more like disordered networks. The arrangement of particles in a solid strongly influences its properties, including hardness, strength, and thermal conductivity.

Solids arise when temperature and pressure conditions favor strong interparticle interactions and reduced mobility. Solids can undergo phase transitions, such as melting to a liquid upon heating or sublimation to a gas directly for some materials. Many substances also exhibit solid-solid transitions, known as polymorphism, where different crystal structures exist at different temperatures or pressures.

Common solids include ice, metals, silicates, carbon in diamond and graphite forms, polymers, and glasses. Water ice has several crystalline forms; graphite and diamond are allotropes of carbon with very different properties; glass is an amorphous solid. The study of phase solids intersects crystallography, metallurgy, electronics, and materials science, influencing the design of alloys, semiconductors, ceramics, and protective coatings.

See also: phase diagram, crystallography, polymorphism, melting, solid-solid phase transition.