Manganese Oxide Phases

The magnetism of manganese oxides is particularly strong, with the diversity of their magnetic properties being based on the electronic flexibility of the manganese 

At this point, the main interest will concern Mn (3d ), Mn (3d ), and Mn  

As a result, the measured g-factor values will therefore be dose to the free-dectron value (ge = 2.0023), and the magnetic anisotropies will be small. Mn has one extra electron compared to Although transition-metal ions with more than three 

The above-described overview of the properties of manganese ions shows that, in manganese oxides, there will be a strong correlation between electronic systems 

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Consider the reaction 3Mn203(s) == 2Mn304(s) + (l/2)02(g). Utilizing the data tabulated below, estimate the temperature at which the equilibrium pressure of 02(g) over the two manganese oxide phases is 0.20 atm. State any assumptions that you make. 

More than 20 manganese oxide phases have been described from continental manganese deposits, but very few of these minerals have been positively identified from marine environments (Table 3). Useful summaries of the nature and nomenclature of the marine manganese minerals include those of Cronan (1976b), R. G. Bums and V. M. Burns (1979), and Post (1999). Marine manganese oxides are hydrous phases usually with poor crystallinity. They are often intimately intergrown with other phases, particularly iron-oxy-hydroxides and hydrous iron oxides. Marine manganese-oxide minerals host a variety of minor elements of economic... 

The major manganese-oxide phases found in ferromanganese cmsts and nodules are todorokite, bimessite, and vemadite (e.g., R. G. Bums and... 

Oxides of manganese and iron. Acidified hydroxylamine hydrochloride releases metals from the manganese oxide phase with minimal attack on the iron oxide phases. Amorphous and crystalline forms of iron oxides can be discriminated between by extracting with acid ammonium oxalate in the dark and under UV light, respectively. 

Figure 19.5 Polyhedral presentations of the costal structures of some manganese oxide phases, (a) Pyrolusite (b) Ramsdellite (c) Hollandite (d) Bixbyite (e) Manganosite (f) X-Mn02 ...

Magnetic Properties of Selected Manganese Oxide Phases The Manifestation of Magnetic Frustration... 

For the supported samples the use of the coating technique, with the hydroxide precursor, leads to the most active catalysts xMnC and manganese oxide phases were XRD detectable. Moreover, for this precursor, supported 6.8MnC and unsupported Mnc samples show comparable activities, in relation with the dispersion effect of the support. 

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