Ad
related to: interstitial vs substitutional solid materials chemistry
Search results
Results From The WOW.Com Content Network
Hume-Rothery rules, named after William Hume-Rothery, are a set of basic rules that describe the conditions under which an element could dissolve in a metal, forming a solid solution. There are two sets of rules; one refers to substitutional solid solutions, and the other refers to interstitial solid solutions.
Interstitial solid solutions form when the solute atom is small enough (radii up to 57% the radii of the parent atoms) [2] to fit at interstitial sites between the solvent atoms. The atoms crowd into the interstitial sites, causing the bonds of the solvent atoms to compress and thus deform (this rationale can be explained with Pauling's rules ...
The propensity for any two substances to form a solid solution is a complicated matter involving the chemical, crystallographic, and quantum properties of the substances in question. Substitutional solid solutions, in accordance with the Hume-Rothery rules, may form if the solute and solvent have: Similar atomic radii (15% or less difference)
Interstitial atoms (blue) occupy some of the spaces within a lattice of larger atoms (red) In materials science, an interstitial defect is a type of point crystallographic defect where an atom of the same or of a different type, occupies an interstitial site in the crystal structure.
In some materials, neighboring atoms actually move away from a vacancy, because they experience attraction from atoms in the surroundings. A vacancy (or pair of vacancies in an ionic solid) is sometimes called a Schottky defect. Interstitial defects are atoms that occupy a site in the crystal structure at which there is usually not an atom ...
Notice the strain in the lattice that the solute atoms cause. The interstitial solute could be carbon in iron for example. The carbon atoms in the interstitial sites of the lattice creates a stress field that impedes dislocation movement. This is a schematic illustrating how the lattice is strained by the addition of substitutional solute.
In crystallography, interstitial sites, holes or voids are the empty space that exists between the packing of atoms (spheres) in the crystal structure. [ citation needed ] The holes are easy to see if you try to pack circles together; no matter how close you get them or how you arrange them, you will have empty space in between.
Assume the chemical composition is AX, with A being the cation and X being the anion. (The following assumes that X is a diatomic gas such as oxygen and therefore cation A has a +2 charge. Note that materials with this defect structure are often used in oxygen sensors.) In the reduced n-type, there are excess cations on the interstitial sites: A ×