koostisestkrystalstruktuur

Composite crystal structure refers to a crystal in which two or more distinct components form a single, extended lattice with a regular arrangement of atoms. In such structures, interfaces or domains of different composition or crystallographic order repeat in space, creating a periodic or quasi-periodic architecture. This contrasts with homogeneous solid solutions, where lattice sites are occupied randomly by different elements.

Common forms include solid solutions where different elements substitute into the same lattice (substitutional or interstitial), ordered intermetallics and superlattices in which the components occupy specific sublattices or layered sequences, and intergrowths or polytypes where two crystal structures share a common lattice but differ in stacking order.

Formation typically results from diffusion and phase behavior during solidification, annealing, or cooling under particular temperature and composition conditions. Lattice mismatch between components can induce strain and dislocations at interfaces, influencing stability and properties.

Characterization relies on diffraction and microscopy: X-ray or neutron diffraction reveals periodicity and phase composition, while transmission electron microscopy shows interfaces and stacking. Analytical methods such as Rietveld refinement extract structural details from diffraction data.

Properties of composite crystal structures are highly tunable through composition and architecture, affecting mechanical strength, electronic and optical behavior, and catalytic activity. They underpin technologies such as semiconductor superlattices, layered oxide materials, and advanced structural alloys.