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Inverse spinel structures have a different cation distribution in that all of the A cations and half of the B cations occupy octahedral sites, while the other half of the B cations occupy tetrahedral sites. An example of an inverse spinel is Fe 3 O 4, if the Fe 2+ (A 2+) ions are d 6 high-spin and the Fe 3+ (B 3+) ions are d 5 high-spin.
Maghemite (Fe 2 O 3, γ-Fe 2 O 3) is a member of the family of iron oxides.It has the same formula as hematite, but the same spinel ferrite structure as magnetite (Fe 3 O 4) and is also ferrimagnetic.
The mineral ceylonite has the chemical composition of (Mg, Fe 2+) Al 2 O 4, putting it into a group of minerals known as the spinel group, or the oxide spinels. The oxide spinels have a formula of the model [A][B] 2 O 4; where [A] is commonly Fe 2+, Mg 2+, or Mn 2+, and [B] is Fe 3+, Al 3+, or Cr 3+. It is an iron-rich variety of the spinel ...
Polyhedral representation of spinel MgAl 2 O 4. Spinel (/ s p ɪ ˈ n ɛ l, ˈ s p ɪ n əl / [7]) is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl 2 O 4 in the cubic crystal system. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals. [5]
Ringwoodite is polymorphous with forsterite, Mg 2 SiO 4, and has a spinel structure.Spinel group minerals crystallize in the isometric system with an octahedral habit. Olivine is most abundant in the upper mantle, above about 410 km (250 mi); the olivine polymorphs wadsleyite and ringwoodite are thought to dominate the transition zone of the mantle, a zone present from about 410 to 660 km
Filipstadite is a very rare mineral [4] of the spinel group, with the formula (Mn,Mg)(Sb 5+ 0.5 Fe 3 + 0.5)O 4. [5] It is isometric, [3] although it was previously thought to be orthorhombic. When compared to a typical spinel, both the octahedral and tetrahedral sites are split due to cation ordering. [3] Filipstadite is chemically close to ...
For typical ionic solids, the cations are smaller than the anions, and each cation is surrounded by coordinated anions which form a polyhedron.The sum of the ionic radii determines the cation-anion distance, while the cation-anion radius ratio + / (or /) determines the coordination number (C.N.) of the cation, as well as the shape of the coordinated polyhedron of anions.
Commonly known as magic blue, it is the hexachloroantimonate salt of an amine radical cation. It is a blue solid that reacts with many solvents but is soluble in acetonitrile . The compound is a popular oxidizing agent in organic and organometallic chemistry , with a reduction potential of 0.67 V versus ferrocene /ferrocenium ( acetonitrile ...