Manganese(II,III) oxide is the manganese oxide with the chemical compound with formula Mn₃O₄.

Manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

is present in two

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...

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

Preparation

Mn₃O₄ formed when any manganese oxide is heated in air above 1000 °C. Considerable research has centred on producing nanocrystalline 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 () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , a diminutive form of ''spine,'' in reference to its pointed crystals. Prop ...

structure, where the oxide ions are cubic close packed and the Mn^II occupy tetrahedral sites and the Mn^III octahedral sites. The structure is distorted due to the Jahn–Teller effect. At room temperature Mn₃O₄ is paramagnetic, below 41-43 K, it is

ferrimagnetic A ferrimagnetic material is a material that has populations of atoms with opposing magnetic moments, as in antiferromagnetism, but these moments are unequal in magnitude, so a spontaneous magnetization remains. This can for example occur wh ...

although this has been reported as reducing in nanocrystalline samples to around 39 K.

Uses

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

ferrites Ferrite may refer to: * Ferrite (iron), one of the allotropes of iron that is stable at room temperature and pressure, α-Fe * Ferrite (magnet), a ferromagnetic ceramic material See also * * Ferrite bead, a component placed on the end of a data c ...

e.g. manganese zinc ferrite, and lithium manganese oxide, used in lithium batteries.Process for preparing lithium manganese oxides, U.S Patent number: 6706443,(2004), Horst Krampitz, Gerhard Wohner Manganese tetroxide can also be used as a weighting agent while drilling reservoir sections in oil and gas wells.

References

{{oxygen compounds Manganese compounds Transition metal oxides Mixed valence compounds