Library

Language
Preferred search index
Number of Hits per Page
Default Sort Criterion
Default Sort Ordering
Size of Search History
Default Email Address
Default Export Format
Default Export Encoding
Facet list arrangement
Maximum number of values per filter
Auto Completion
Feed Format
Maximum Number of Items per Feed
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 112 (1998), S. 217-222 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 69 (1992), S. 831-834 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract CEMS and X-ray diffraction of rust layers on an iron coupon corroded in a 0.02 M KCl solution show that there exists a magnetite layer below an outer lepidocrocite layer. The 10 K spectrum displays three ferric sextets in its lepidocrocite part with fields of 448, 422 and 387 kOe respectively. They are attributed to Fe3+ ions having zero, one and more Cl− ions as first nearest neighbours. The Cl− ions do not seem to be ordered.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 69 (1992), S. 827-830 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The crystallographic structure of Ni(II)−Fe(III) hydroxy-chloride green rusts obtained by oxidation of a FexNi1−x(OH)2 precipitate is isomorphous with that of the ferrousferric green rust one and independent of the value of P=Fe/Ni. Mössbauer spectra exhibit two quadrupole doublets after further oxidation of the compounds which correspond to a formula (3-x)Ni(OH)2 · xFeOOH · Fe(OH)2Cl. The Fe3+ ions are found to occupy preferentially the sites close to the Cl− ions and the Ni2+ those far from them. However the ordering of the Fe3+ ions is not perfect.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Mössbauer spectra of green rust one run at 78 and 4.4 K exhibit two ferrous and one ferric sites in the 2/1/1 intensity ratio. Chemical formula is set at 3Fe(OH)2, Fe(OH)2Cl, nH2O. By replacing Fe2+ with Ni2+ ions, the compound is stabilized and the structure is determined on a ABiBCiCai stacking sequence. Space group is P3121 with an hexagonal unit cell of parameters a=6.17 and c=23.5 A0.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Mössbauer analysis of archeological iron artifacts allows to determine mainly the presence of the β ferric oxyhydroxide, akaganeite, in the rust products. This confirms the role of Cl− ions in the environment leading to difficult preservation in a museum.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 57 (1990), S. 2037-2043 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The formation of goethite is simulated by stirring up in the presence of air a mixture of FeSO4, 7H2O and NaOH in the 1∶5 ratio at different initial concentrationC of ferrous ions. Mössbauer spectra of the oxidation end products display the sextet of goethite (αFeOOH) and a paramagnetic ferric doublet increasing whenC decreases; the crystal structure of goethite is also being modified. At a critical low concentration, the orthorhombic structure is no longer justified; inactive α′-FeOOH, which has a similar X-ray diffraction pattern as δ-FeOOH is obtained. All these compounds are crystallographically related.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Green rust 2 is usually obtained by oxidizing an initial mixture of FeSO4 and NaOH solutions and a complete oxidation leads mainly towards γ oxyhydroxide known as lepidorocite. By adding some NiSO4 one can stop at the first stage and Mössbauer spectra reveral only ferric doublets. This implies that the initial formula 4Fe(OH)2, 2FeOOH, FeSO4 of green rust 2 must be replaced byxNi(OH)2, (6−x)FeOOH, NiSO4, wherex scans from 2 to 4. It also means that all initial ferrous ions become oxidized into the ferric state leaving the Ni2+ ions unchanged. Therefore the end product of oxidation is the nickel containing green rust 2 at the place of the usual lepidocrocite.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fe(II)-Fe(III) hydroxy-sulphate Green Rust 2, GR2(SO4 –), is obtained by microbially induced corrosion of steel. Transmission Mössbauer spectroscopy (TMS) was used to characterise the corrosion products of steel sheet piles under the biofilm at low sea-water level in a harbour. To understand the process, iron coupons maintained in aqueous solutions of 4 M NaCl and 0.1 M NaHCO3 of pH 7.4 were studied by X ray diffraction and conversion electron Mössbauer spectroscopy (CEMS) at 78 K. The Fe(II)-Fe(III) hydroxy-carbonate, GR1(CO3 –), covers the surface, as predicted by the Eh-pH diagram.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    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 ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...