Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 90 (1994), S. 389-394 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The oxidation of Fe(OH)2 in the presence of Cl− or CO 3 2− ions leads, in the first stage of the reaction, to chloride-containing green rust one (GR1), 3Fe(OH)2· Fe(OH)2Cl·nH2O, or carbonate-containing GR1, 4Fe(OH)2·Fe2(OH)4CO3·nH2O, respectively. These GR1 compounds give the ferric oxyhydroxides by further oxidation. If a hydroxide Ni x Fe1−x (OH)2 is initially precipitated, the reaction leads to a nickelous-ferric compound isomorphous to the ferrous-ferric GR1, but stable with respect to the oxidizing action of air. Similarly, the oxidation of a nickelous-ferrous hydroxide, in the presence of excess OH− ions, leads to a nickelous-ferric GR1, a layered hydroxide with anionic interlayers made of OH− ions and water molecules. The Mössbauer spectra of these nickelousferric GR1 display two ferric doublets, D0 withIS=0.34 mm/s andQS=0.45 mm/s and D1 withIS=0.36 mm/s andQS=0.86 mm/s. The existence of a ferrous-ferric GR1 incorporating OH− ions, a compound never observed so far, is strongly suspected.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 90 (1994), S. 395-400 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Sodium carbonate Na2CO3 is added to a solution containing an Fe(OH)2 precipitate in order to study the influence of CO 3 2− ions on the oxidation of ferrous hydroxide. The first stage of the reaction leads to a ferrous-ferric compound, the carbonate green rust one (GR1), identified by its X-ray diffraction pattern. The Mössbauer spectrum at 78 K of this GR1 displays two ferrous doublets and one ferric doublet in the 3∶1∶2 abundance ratio. The quadrupole splittingsQS are 2.91, 2.58 and 0.42 mm/s, respectively, and the isomer shifts 75 are 1.25, 1.25 and 0.47 mm/s respectively. These values are very close to those of the three doublets of the chloride GR1, 3Fe(OH)2Cl·Fe(OH)2Cl·nH2O. This fact confirms that the crystallographic structures of these two GR1s are similar, formed by the stacking of hydroxide layers and interlayers containing the considered anions (Cl− or CO 3 2− ) and water molecules. The chemical formula of carbonate GR1 is Fe 4 (II) Fe 2 (III) (OH)12CO3·nH2O, and its standard chemical potential -853 900 cal/mol ifn=0. The second stage of the reaction is the oxidation of GR1, which leads to α-FeOOH goethite.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...