Ferric+Oxide


 * Iron(III) oxide** or **ferric oxide** is the [|inorganic compound] with the formula Fe2O3. It is one of the three main [|oxides] of [|iron], the other two being [|iron(II) oxide] (FeO), which is rare, and [|iron(II,III) oxide] (Fe3O4), which also occurs naturally as the mineral [|magnetite]. As the mineral known as [|hematite], Fe2O3 is the main source of the iron for the steel industry. Fe2O3 is [|ferromagnetic], dark red, and readily attacked by acids. [|Rust] is often called iron(III) oxide, and to some extent this label is useful, because rust shares several properties and has a similar composition. To a chemist, rust is considered an ill-defined material, described as //hydrated// ferric oxide.

Fe2O3 can be obtained in various [|polymorphs]. In the main ones, α and γ, iron adopts octahedral coordination geometry. That is, each Fe center is bound to six oxygen [|ligands].
 * Structure:**

**Alpha Phase:**
α-Fe2O3 has the [|rhombohedral], [|corundum] (α-Al2O3) structure and is the most common form. It occurs naturally as the mineral [|hematite] which is mined as the main [|ore] of iron. It is [|antiferromagnetic] below ~260 K (Morin transition temperature), and weak [|antiferromagnetic] between 260 K and 950 K [|Néel temperature] It is easy to prepare using both [|thermal decomposition] and precipitation in the liquid phase. Its magnetic properties are dependent on many factors, e.g. pressure, particle size, and magnetic field intensity.