Phase separation scenario for manganese oxides

Microbial formation of manganese oxides.

Microbial manganese oxidation was demonstrated at high Mn concentrations (5 g/liter) in bacterial cultures in the presence of a microalga. The structure of the oxide produced varied depending on the bacterial strain and mode of culture. A nonaxenic, acid-tolerant microalga, a Chlamydomonas sp., was found to mediate formation of manganite (gamma-MnOOH). Bacteria isolated from associations with c...

Colossal Magnetoresistance in Ce Doped Manganese Oxides

Structural stability of lithium manganese oxides

We have studied stability of lithium-manganese oxides using density functional theory in the local density and generalized gradient approximation ~GGA!. In particular, the effect of spin-polarization and magnetic ordering on the relative stability of various structures is investigated. At all lithium compositions the effect of spin polarization is large, although it does not affect different st...

A Study of Cerium–Manganese Mixed Oxides for Oxidation Catalysis

Cerium–manganese mixed oxides with compositions of Ce0.5Mn0.5O1.75 and Ce0.8Mn0.2O1.9 were prepared by the citric-acid (Pechini) method and their catalytic properties were compared to CeO2 and Mn2O3. The mixed oxides exhibited higher specific rates than either CeO2 or Mn2O3 for oxidation of both methane and nbutane. While XRD measurements of the mixed oxides suggested that the materials had pri...

Characterization and reactivity of biogenic manganese oxides for ciprofloxacin oxidation.

Biogenic manganese oxides (BioMnOx) were synthesized by the oxidation of Mn(II) with Mn-oxidizing bacteria Pseudomonas sp. G7 under different initial pH values and Mn(II) dosages, and were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and UV-Vis absorption spectroscopy. The crystal structure and Mn oxidation states of BioMnOx depended on the initial pH and Mn(II) dosages...