Topotactic
Encyclopedia
In chemistry
, a topotactic transition involves a structural change to a crystalline solid, which may include loss or gain of material, so that the final lattice is related to that of the original material by one or more crystallographically equivalent, orientational relationships.
An example is a transition in which the relative structure of the anionic array is unaltered but the cations reorganize as in:
β-Li2ZnSiO4 ⇒ γ-Li2ZnSiO4
An alternate example is the oxidation of magnetite
to maghemite
.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, a topotactic transition involves a structural change to a crystalline solid, which may include loss or gain of material, so that the final lattice is related to that of the original material by one or more crystallographically equivalent, orientational relationships.
An example is a transition in which the relative structure of the anionic array is unaltered but the cations reorganize as in:
β-Li2ZnSiO4 ⇒ γ-Li2ZnSiO4
An alternate example is the oxidation of magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
to maghemite
Maghemite
Maghemite is a member of the family of iron oxides. It has the same structure as magnetite, that is, it is spinel ferrite and is also ferrimagnetic.Maghemite can be considered as an Fe-deficient magnetite with formula...
.