Automated Mössbauer spectroscopy in the field and monitoring of fougerite

Rodionov, D.; Klingelhöfer, G.; Bernhardt, B.; Schröder, Christian; Blumers, M.; Kane, S. N.; Trolard, Fabienne; Bourrié, Guilhem; Génin, J.‐M. R.

doi:10.1007/s10751-006-9371-9

Cited by 11 publications

(5 citation statements)

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“…Characterization of the natural material was complicated by the fact that the Fe 3+ molar fraction x = (Fe 3+ /Fe tot ), as determined by Mössbauer spectroscopy, was always found to be greater thanˆÙ¯(e.g. Génin et al, 1998Génin et al, , 2005Féder et al, 2005;Rodionov et al, 2006). In contrast, synthetic samples produced by coprecipitation always had x =ˆÙ˘ÀˆÙ¯, as in any other LDH (Génin et al, 2006b;, and compositions such as Fe 2+ 6 Fe 3+ 2 (OH) 16 CO 3 •3H 2 O and Fe 2+ 4 Fe 3+ 2 (OH) 12 CO 3 •3H 2 O (Génin et al, 2005).…”

Section: àmentioning

confidence: 93%

Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides

Mills¹,

Christy²,

Génin³

et al. 2012

Mineral. mag.

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Layered double hydroxide (LDH) compounds are characterized by structures in which layers with a brucite-like structure carry a net positive charge, usually due to the partial substitution of trivalent octahedrally coordinated cations for divalent cations, giving a general layer formula [(M1–x2+M3+x)(OH)2]x+. This positive charge is balanced by anions which are intercalated between the layers. Intercalated molecular water typically provides hydrogen bonding between the brucite layers. In addition to synthetic compounds, some of which have significant industrial applications, more than 40 mineral species conform to this description. Hydrotalcite, Mg6Al2(OH)16[CO3]·4H2O, as the longest-known example, is the archetype of this supergroup of minerals. We review the history, chemistry, crystal structure, polytypic variation and status of all hydrotalcite-supergroup species reported to date. The dominant divalent cations,M2+, that have been reported in hydrotalcite supergroup minerals are Mg, Ca, Mn, Fe, Ni, Cu and Zn; the dominant trivalent cations,M3+, are Al, Mn, Fe, Co and Ni. The most common intercalated anions are (CO3)2–, (SO4)2–and Cl–; and OH–, S2–and [Sb(OH)6]– have also been reported. Some species contain intercalated cationic or neutral complexes such as [Na(H2O)6]+or [MgSO4]0. We define eight groups within the supergroup on the basis of a combination of criteria. These are (1) the hydrotalcite group, withM2+:M3+= 3:1 (layer spacing ∼7.8 Å); (2) the quintinite group, withM2+:M3+= 2:1 (layer spacing ∼7.8 Å); (3) the fougèrite group, withM2+= Fe2+,M3+= Fe3+in a range of ratios, and with O2– replacing OH– in the brucite module to maintain charge balance (layer spacing ∼7.8 Å); (4) the woodwardite group, with variableM2+:M3+and interlayer [SO4]2 –, leading to an expanded layer spacing of ∼8.9 Å; (5) the cualstibite group, with interlayer [Sb(OH)6]– and a layer spacing of ∼9.7 Å; (6) the glaucocerinite group, with interlayer [SO4]2– as in the woodwardite group, and with additional interlayer H2O molecules that further expand the layer spacing to ∼11 Å; (7) the wermlandite group, with a layer spacing of ∼11 Å, in which cationic complexes occur with anions between the brucite-like layers; and (8) the hydrocalumite group, withM2+= Ca2+andM3+= Al, which contains brucite-like layers in which the Ca:Al ratio is 2:1 and the large cation, Ca2+, is coordinated to a seventh ligand of 'interlayer' water.The principal mineral status changes are as follows. (1) The names manasseite, sjögrenite and barbertonite are discredited; these minerals are the 2H polytypes of hydrotalcite, pyroaurite and stichtite, respectively. Cyanophyllite is discredited as it is the 1M polytype of cualstibite. (2) The mineral formerly described as fougèrite has been found to be an intimate intergrowth of two phases with distinct Fe2+:Fe3+ratios. The phase with Fe2+:Fe3+= 2:1 retains the name fougèrite; that with Fe2+:Fe3+= 1:2 is defined as the new species trébeurdenite. (3) The new minerals omsite (IMA2012-025), Ni2Fe3+(OH)6[Sb(OH)6], and mössbauerite (IMA2012-049), Fe3+6O4(OH)8[CO3]·3H2O, which are both in the hydrotalcite supergroup are included in the discussion. (4) Jamborite, carrboydite, zincaluminite, motukoreaite, natroglaucocerinite, brugnatellite and muskoxite are identified as questionable species which need further investigation in order to verify their structure and composition. (5) The ranges of compositions currently ascribed to motukoreaite and muskoxite may each represent more than one species. The same applies to the approved species hydrowoodwardite and hydrocalumite. (6) Several unnamed minerals have been reported which are likely to represent additional species within the supergroup.This report has been approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association, voting proposal 12-B.We also propose a compact notation for identifying synthetic LDH phases, for use by chemists as a preferred alternative to the current widespread misuse of mineral names.

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Section: àmentioning

confidence: 93%

Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides

Mills¹,

Christy²,

Génin³

et al. 2012

Mineral. mag.

Self Cite

367

325

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“…It will provide a useful characterisation of the GR(x) * compounds for the full range of x values that scan from 1/3 to 1 obtained by using X-ray diffraction (XRD) and c-ray backscattered Mö ssbauer spectroscopy at room temperature. The same apparatus used recently for field experiments when studying in situ the mineralogical transformations of fougerite (Féder et al, 2005;Rodionov et al, 2006), i.e. the miniaturised Mö ssbauer spectrometer (MIMOSII) developed by Klingelhö fer et al (1996) was used here for the characterisation of synthetic GR compounds.…”

Section: Introductionmentioning

confidence: 99%

Oxidation modes and thermodynamics of FeII–III oxyhydroxycarbonate green rust: Dissolution–precipitation versus in situ deprotonation

Ruby

Abdelmoula²,

Naille³

et al. 2010

Geochimica et Cosmochimica Acta

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Fe II-III hydroxycarbonate green rust GR(CO 3 2À ), Fe II 4 Fe III 2 (OH) 12 CO 3 Á3H 2 O, is oxidized in aqueous solutions with varying reaction kinetics. Rapid oxidation with either H 2 O 2 or dissolved oxygen under neutral and alkaline conditions leads to the formation of ferric oxyhydroxycarbonate GR(CO 3 2À ) * , Fe III 6 O 12 H 8 CO 3 Á3H 2 O, via a solid-state reaction. By decreasing the flow of oxygen bubbled in the solution, goethite a-FeOOH forms by dissolution-precipitation mechanism whereas a mixture of non-stoichiometric magnetite Fe (3Àx) O 4 and goethite is observed for lower oxidation rates. The intermediate Fe II-III oxyhydroxycarbonate of formula Fe II 6(1Àx) Fe III 6x O 12 H 2(7À3x) CO 3 Á3H 2 O, i.e. GR(x) * for which x e [1/3, 1], is the synthetic compound that is homologous to the fougerite mineral present in hydromorphic gleysol; in situ oxidation accounts for the variation of ferric molar fraction x = [Fe III ]/{[Fe II ]+[Fe III ]} observed in the field as a function of depth and season but limited to the range [1/3, 2/3]. The domain of stability for partially oxidized green rust is observed in the E h -pH Pourbaix diagrams if thermodynamic properties of GR(x) * is compared with those of lepidocrocite, c-FeOOH, and goethite, a-FeOOH. Electrochemical equilibrium between GR(x) * and Fe II in solution corresponds to E h -pH conditions close to those measured in the field. Therefore, the reductive dissolution of GR(x) * can explain the relatively large concentration of Fe II measured in aqueous medium of hydromorphic soils containing fougerite.

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“…In addition, we can observe that the most prosperous periods of agropastoral activities correspond to the optima of the Roman civilization and the Medieval era. The abandonment of 14 C datation and palynological determinations (modified from [2]).…”

Section: Resultsmentioning

confidence: 99%

“…With the progress of in situ instruments and sensors developed for spatial research and Mars exploration, a miniaturized Mössbauer spectrometer, Mimos II, was built up [13,14]. The signal emitted by the source of the spectrometer is recorded using reflection-based geometry, which is not influenced by the thickness of the sample, unlike conventional transmission geometry [15].…”

Section: Methodsmentioning

confidence: 99%

Geochemical Methods to Assess Agriculture Sustainability

Trolard¹,

David²,

Bourrié³

2020

Applied Geochemistry With Case Studies on Geological Formations, Exploration Techniques and Environmental Issues

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Facing global changes and the challenge of food security, scientists are being questioned by decision-makers and stakeholders on the sustainability of agrosystems. The main difficulty in dealing with this question is to obtain enough data over long periods of time. Monitoring slow drifts and weak noises is needed to forecast tipping points that can jeopardize the present steady state. High-resolution datations by radiocarbon coupled with detailed palynological determinations in sediments, historical archives on yields and crop quality, and high-frequency field in situ measurements give information on climatic changes from multi-secular to seasonal and hourly time scales. In the long term, climatic forcing dominates agriculture performance, at that time only organic agriculture, with oscillations between prosperity and misery driven by climate and intermediated by civilization flourishing and collapsing; in the medium term, in modern agriculture, irrigation provides a provisional buffering effect on yield and crop quality despite present warming; in the short term, either under non-fertilized forested ecosystem or intensive rice cropping, the same patterns are evidenced and point to the importance of soil microflora shifting from aerobiosis to anaerobiosis. In all cases, geochemistry offers appropriate tools to decipher the climate-soil-agriculture complex interplay.

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Automated Mössbauer spectroscopy in the field and monitoring of fougerite

Cited by 11 publications

References 4 publications

Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides

Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides

Oxidation modes and thermodynamics of FeII–III oxyhydroxycarbonate green rust: Dissolution–precipitation versus in situ deprotonation

Geochemical Methods to Assess Agriculture Sustainability

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