Manganese oxide is the chemical compound with formula Mn₃O₄. Manganese

Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

 is present in two oxidation state

Oxidation state

In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...

s +2 and +3 and the formula is sometimes written as MnO.Mn₂O₃. Mn₃O₄ is found in nature as the mineral hausmannite

Hausmannite

Hausmannite is a complex oxide of manganese containing both di- and tri-valent manganese. The formula can be represented as Mn2+Mn3+2O4. It belongs to the spinel group and forms tetragonal crystals...

.

Preparation

Mn₃O₄ formed when any manganese oxide is heated in air above 1000°C. Considerable research has centred on producing nano-crystalline Mn₃O₄ and various syntheses that involve oxidation of Mn^II or reduction of Mn^VI.

Reactions

Mn₃O₄ has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide ; the decomposition of NO, the reduction of nitrobenzene and the catalytic combustion of organic compounds

Structure

Mn₃O₄ has the spinel

Spinel

Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...

 structure, where the oxide ions are cubic close packed and the Mn^II occupy octahedral sites and the Mn^III tetrahedral sites. The structure is distorted due to a Jahn-Teller effect. At room temperature Mn₃O₄ is paramagnetic, below 41-43 K, it is ferrimagnetic. although this has been reported as reducing in nano-crystalline samples to around 39 K

Uses

Mn₃O₄ is sometimes used as a starting material in the production of soft ferrites

Ferrite (magnet)

Ferrites are chemical compounds consisting of ceramic materials with iron oxide as their principal component. Many of them are magnetic materials and they are used to make permanent magnets, ferrite cores for transformers, and in various other applications.Many ferrites are spinels with the...

e.g. manganese zinc ferrite, and lithium manganese oxide, used in lithium batteries.