Manganese(III) oxide a structure related to the spinel structure of MnO where the oxide ions are cubic close packed. This is similar to the relationship between γ-FeO and FeO. γ-MnO is ferrimagnetic with a Néel temperature of 39 K. Manganese(III) oxide Manganese(III) oxide is a chemical compound with the formula MnO. Heating MnO in air at below 800 °C produces α-MnO (higher temperatures produce MnO). γ-MnO can be produced by oxidation followed by dehydration of manganese(II) hydroxide. Many preparations of nano-crystalline MnO have been reported, for example syntheses involving oxidation of Mn salts or reduction of MnO. Manganese (III) oxide is formed
Manganese battery and the alkaline battery normally use industrially produced manganese dioxide because naturally occurring manganese dioxide contains impurities. In the 20th century, manganese dioxide was widely used as the cathodic for commercial disposable dry batteries of both the standard (zinc-carbon) and alkaline types. Manganese comprises about 1000 ppm (0.1%) of the Earth's crust, the 12th most abundant of the crust's elements. Soil contains 7–9000 ppm of manganese with an average of 440 ppm. Seawater has only 10 ppm manganese and the atmosphere contains 0.01 µg/m. Manganese occurs principally as pyrolusite (MnO), braunite, (MnMn)(SiO), psilomelane (Ba,HO)MnO, and to a lesser extent