Solid solutions

Mixing of two crystalline solids that coexist as a new crystalline solid, or crystal lattice. The mixing can be accomplished by combining the two solids when they have been melted into liquids at high temperatures and then cooling the result to form the new solid or by depositing vapours of the starting materials onto substrates to form thin films. As with liquids, solids have different degrees of mutual solubility, depending on their chemical properties and crystalline structure, which determine how their atoms fit together in the mixed crystal lattice.

The mixed lattice may be substitutional, in which the atoms of one starting crystal replace those of the other, or interstitial, in which the atoms occupy positions normally vacant in the lattice. solid-state solution of one or more solutes in a solvent. Such a mixture is considered a solution rather than a compoundwhen the crystal structure of the solvent remains unchanged by addition of the solutes, and when the mixture remains in a single homogeneous phase.


At three different concentrations, the material will be solid until it's heated to its melting point, and then become liquid at that same temperature:

The unalloyed extreme left

The unalloyed extreme right

The dip in the center (the eutectic composition).