Library

X
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
    Transformation of Fe(II)-Fe(III) Hydroxysulphite into Hydroxysulphate Green Rusts (1998)
    Springer
    Hyperfine interactions 112 (1998), S. 217-222 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fe(II)-Fe(III) hydroxysulphite Green Rust 1, GR1(SO3 2−), can be obtained by oxidation of Fe(OH)2 precipitates in aqueous solution and characterised by X-ray diffraction and Mössbauer spectroscopy. In contrast to other Green Rusts (GRs) which then oxidise directly into ferric oxyhydroxides and magnetite, GR1(SO3 2−) first oxidises into a Green Rust two compound, as identified by X-ray diffraction. Mössbauer analysis reveals that this GR2 is the Fe(II)-Fe(III) hydroxysulphate, GR2(SO4 2−). Such an oxidation process, GR1(SO3 2−) → GR2(SO4 2−) confirms that the average oxidation number of Fe increases according to the chemical formulae previously proposed, [FeII 6FeIII 2(OH)16]2+[SO3 · mH2O]2−, and [FeII 4FeIII 2(OH)12]2+[SO4 · nH2O]2− for GR1(SO3 2−) and GR2(SO4 2−) with oxidation numbers of 2.25 and 2.33, respectively. The process implies likely the presence of sulphate ions inherent to the oxidation of sulphite in the solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010845107110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Evidence for the Fe(II)-Fe(III) Green Rust "Fougerite" Mineral Occurrence in a Hydromorphic Soil and Its Transformation with Depth (1998)
    Springer
    Hyperfine interactions 112 (1998), S. 235-238 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Mössbauer spectroscopy is used to characterize a Green Rust as a natural mineral for the first time. Samples are taken from a hydromorphic soil under the forest at Fougères (Brittany, France) during spring season. Spectra are compared with those of synthetic Green Rusts (GRs), i.e. hydroxy-chloride, -sulphate, -carbonate and display one ferric and one or two ferrous sites. Fe(II)/Fe(III) abundances ratio cannot be attributed definitely to one of those stoichiometric compounds. Therefore, the counter-anion species cannot be specified even though hyperfine parameters perfectly match values of synthetic samples. The Fe(II)/Fe(III) ratio obtained from the Mössbauer spectra decreases with sampling depth. The "fougerite" originates likely from the reduction of deeper Fe(III)-mineral species by anoxic waterlogging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010802508927
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Preparation and Eh--pH diagrams of Fe(II)--Fe(III) green rust compounds; hyperfine interaction characteristics and stoichiometry of hydroxy-chloride, -sulphate and -carbonate (1998)
    Springer
    Hyperfine interactions 111 (1998), S. 313-318 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fe(II)--Fe(III) hydroxy-chloride, -sulphate and -carbonate were prepared by oxidation of a ferrous hydroxide precipitate in anion-containing aqueous solutions. The compounds are characterized by monitoring the redox potential Eh and the pH of stochiometric suspension vs time with the appropriate concentration ratios. X-ray diffraction allows us to characterize the crystal structure by distinguishing “green rust one” (GR1) from “green rust two” (GR2). Since green rusts (GRs) are of a pyroaurite-sjögrenite-like structure, i.e., consisting of intercalated foreign anions and water molecules in the interlayers between the brucite-like layers of Fe(OH)2, their chemical formulae can be determined from the Mössbauer spectra. Three quadrupole doublets are observed: D1 and D2 correspond to a ferrous state with isomershift IS of about 1.27 mm s-1 and quadrupole splittings QS of about 2.85 and 2.60 mm s-1, respectively, whereas D3 corresponds to a ferric state with IS and QS of about 0.4 mm s-1. The hyperfine parameters of these doublets are similar from one green rust to another but their intensity ratios vary considerably. Finally, Eh and pH equilibrium diagrams of the Fe species in the presence of chloride, sulphate and carbonate anions contained within the water solution are drawn and the thermodynamic conditions of existence and degrees of oxidation of green rusts are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012638724990
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...