Interstitial solid solution
| black = atoms of the base element red = inclusion atoms |
In a solid solution , also interstitial compound or intercalation compound called, is a chemical , non- stoichiometric crystalline compound from at least two elements.
This type of connection is usually found between metal and non-metal , whereby the much smaller atoms of the non-metal ( foreign atoms, intercalation atoms ) occupy interstitial spaces or gaps in the crystal lattice of the metal ( host element, base element ). Inclusion compounds often have metallic properties. Important representatives include iron-carbon , tungsten carbide (WC), Ti 2 H or Fe 2 N.
In the case of an interstitial solid solution, lattice distortions always occur, which widen the crystal lattice, since additional atoms have to be added to the lattice. In order to make this connection possible, the atomic diameter of the foreign atom must only be about 41% of the atomic diameter of the host atom. In addition, the storage capacity is severely limited due to the lattice distortion and the associated stresses . For example, for the iron-carbon compound, it is 0.10% (δ mixed crystal), 2.06% (γ mixed crystal) or 0.02% (α mixed crystal), depending on the temperature. This means that z. B. in an α mixed crystal a maximum of 0.2% carbon (at 723 ° C) to 0.02% (at room temperature) can be dissolved.
See also
- Mixed crystal
- Crystal system
- Iron-carbon diagram
- alloy
- Metallic bond
- Substitution solid solution
- Clathrates
Web links
- Uni Kiel: zero-dimensional defects