Lattice constant

Encyclopedia : L : LA : LAT : Lattice constant

Lattice constant, or a, defines the distance between atoms in crystal lattice. It is a measure of structural compatibility between different materials.

Lattice constants are measured in nanometers, and may differ for different axes in the crystal structure for non-cubic crystals.

Lattice constant matching is important for growth of thin layers of materials on other materials; when the constants differ, strains are introduced into the layer, which prevents epitaxial growth of thicker layers without defects.

Lattice matching, matching of lattice structures between two different semiconductor materials, allows forming of a region of band gap change in the material without introducing a change in crystal structure. It allows construction of advanced light-emitting diodes and diode lasers.

For example, gallium arsenide, aluminium gallium arsenide, and aluminium arsenide have almost identical lattice constant, making it possible to grow almost arbitrarily thick layers of one on the other one.

Lattice constants can be determined by x-ray diffraction.

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.