Menu
Home Explore People Places Arts History Plants & Animals Science Life & Culture Technology
On this page
Manganese(III) oxide
Chemical compound

Manganese(III) oxide is a chemical compound with the formula Mn2O3. It occurs in nature as the mineral bixbyite (recently changed to bixbyite-(Mn)) and is used in the production of ferrites and thermistors.

Related Image Collections Add Image
Profiles
1 Image
We don't have any YouTube videos related to Manganese(III) oxide yet.
We don't have any PDF documents related to Manganese(III) oxide yet.
We don't have any Books related to Manganese(III) oxide yet.
We don't have any archived web articles related to Manganese(III) oxide yet.

Preparation and chemistry

Heating MnO2 in air at below 800 °C produces α-Mn2O3 (higher temperatures produce Mn3O4).3 γ-Mn2O3 can be produced by oxidation followed by dehydration of manganese(II) hydroxide.4 Many preparations of nano-crystalline Mn2O3 have been reported, for example syntheses involving oxidation of MnII salts or reduction of MnO2.567

Manganese(III) oxide is formed by the redox reaction in an alkaline cell:

2 MnO2 + Zn → Mn2O3 + ZnO

Manganese(III) oxide Mn2O3 must not be confused with MnOOH manganese(III) oxyhydroxide. Contrary to Mn2O3, MnOOH is a compound that decomposes at about 300 °C to form MnO2.8

Structure

Mn2O3 is unlike many other transition metal oxides in that it does not adopt the corundum (Al2O3) structure.9 Two forms are generally recognized, α-Mn2O3 and γ-Mn2O3,10 although a high pressure form with the CaIrO3 structure has been reported too.11

α-Mn2O3 has the cubic bixbyite structure, which is an example of a C-type rare earth sesquioxide (Pearson symbol cI80, space group Ia3, #206). The bixbyite structure has been found to be stabilised by the presence of small amounts of Fe3+, pure Mn2O3 has an orthorhombic structure (Pearson symbol oP24, space group Pbca, #61).12 α-Mn2O3 undergoes antiferromagnetic transition at 80 K. 13

γ-Mn2O3 has a structure related to the spinel structure of Mn3O4 where the oxide ions are cubic close packed. This is similar to the relationship between γ-Fe2O3 and Fe3O4.14 γ-Mn2O3 is ferrimagnetic with a Néel temperature of 39 K.15

ε-Mn2O3 takes on a rhombohedral ilmenite structure (the first binary compound known to do so), wherein the manganese cations divided equally into oxidation states 2+ and 4+. ε-Mn2O3 is antiferromagnetic with a Néel temperature of 210 K.16

References

  1. "Bixbyite-(Mn)". https://www.mindat.org/min-691.html ↩

  2. IMA 21-H: Redefinition of bixbyite and definition of bixbyite-(Fe) and bixbyite-(Mn). CNMNC Newsletter, 64, 2021; Mineralogical Magazine, 85, 2021). ↩

  3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1049. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩

  4. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1049. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩

  5. Shuijin Lei; Kaibin Tang; Zhen Fang; Qiangchun Liu; Huagui Zheng (2006). "Preparation of α-Mn2O3 and MnO from thermal decomposition of MnCO3 and control of morphology". Materials Letters. 60: 53. doi:10.1016/j.matlet.2005.07.070. /wiki/Doi_(identifier) ↩

  6. Zhong-Yong Yuan; Tie-Zhen Ren; Gaohui Du; Bao-Lian Su (2004). "A facile preparation of single-crystalline α-Mn2O3 nanorods by ammonia-hydrothermal treatment of MnO2". Chemical Physics Letters. 389 (1–3): 83. doi:10.1016/j.cplett.2004.03.064. /wiki/Doi_(identifier) ↩

  7. Navin Chandra; Sanjeev Bhasin; Meenakshi Sharma; Deepti Pal (2007). "A room temperature process for making Mn2O3 nano-particles and γ-MnOOH nano-rods". Materials Letters. 61 (17): 3728. doi:10.1016/j.matlet.2006.12.024. /wiki/Doi_(identifier) ↩

  8. Thomas Kohler; Thomas Armbruster; Eugen Libowitzky (1997). "Hydrogen Bonding and Jahn-Teller Distortion in Groutite,α-MnOOH, and Manganite,γ-MnOOH, and Their Relations to the Manganese Dioxides Ramsdellite and Pyrolusite". Journal of Solid State Chemistry. 133 (2): 486–500. doi:10.1006/jssc.1997.7516. /wiki/Ramsdellite ↩

  9. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1049. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩

  10. Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6 /wiki/ISBN_(identifier) ↩

  11. High Pressure Phase transition in Mn2O3 to the CaIrO3-type Phase Santillan, J.; Shim, S. American Geophysical Union, Fall Meeting 2005, abstract #MR23B-0050 ↩

  12. Geller S. (1971). "Structure of α-Mn2O3, (Mn0.983Fe0.017)2O3 and (Mn0.37Fe0.63)2O3 and relation to magnetic ordering". Acta Crystallogr B. 27 (4): 821. doi:10.1107/S0567740871002966. /wiki/Doi_(identifier) ↩

  13. Geller S. (1970). "Magnetic and Crystallographic Transitions in Sc+, Cr+, and Ga+ Substituted Mn2O3". Physical Review B. 1 (9): 3763. doi:10.1103/physrevb.1.3763. /wiki/Doi_(identifier) ↩

  14. Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6 /wiki/ISBN_(identifier) ↩

  15. Kim S. H; Choi B. J; Lee G.H.; Oh S. J.; Kim B.; Choi H. C.; Park J; Chang Y. (2005). "Ferrimagnetism in γ-Manganese Sesquioxide (γ−Mn2O3) Nanoparticles". Journal of the Korean Physical Society. 46 (4): 941. ↩

  16. Ovsyannikov, Sergey V.; Tsirlin, Alexander A.; Korobeynikov, Igor V.; Morozova, Natalia V.; Aslandukova, Alena A.; Steinle-Neumann, Gerd; Chariton, Stella; Khandarkhaeva, Saiana; Glazyrin, Konstantin; Wilhelm, Fabrice; Rogalev, Andrei; Dubrovinsky, Leonid (2021-09-06). "Synthesis of Ilmenite-type ε-Mn 2 O 3 and Its Properties". Inorganic Chemistry. 60 (17): 13348–13358. doi:10.1021/acs.inorgchem.1c01666. ISSN 0020-1669. PMID 34415155. S2CID 237242460. https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c01666 ↩