Abstract
A set of synthetic goethites were prepared from Fe3+- and Co2+-nitrate solutions in alkaline media with a Co/(Co + Fe) ratio (xCo) up to 10 mol%. The structural characterization of the resultant solid phases was carried out by X-ray diffraction (XRD). XRD analyses showed that in preparations with xCo <10 mol%, Co-substituted goethite was the only crystalline phase present. Atomic and cell parameters for the samples synthesized were obtained by the Rietveld refinement of the XRD data, and showed that the unit cell in the goethite-like phase is contracted as a function of xCo. Little deviation from the Vegard rule was observed for all unit-cell parameters. Cobalt substitution produces an increase in the surface area of the goethite, as well as an increment in the dehydroxylation temperature. The acid dissolution of all Co-goethites showed an increase in dissolution rate with the Co content, and a congruent behavior was observed. The activation energy for dissolution was obtained two samples. A modified first-order Kabai equation best describes the dissolution data.
© 2015 by Walter de Gruyter Berlin/Boston
Artikel in diesem Heft
- Compositional variability and crystal structural features of guanacoite
- Interferometric study of pyrite surface reactivity in acidic conditions
- White mica domain formation: A model for paragonite, margarite, and muscovite formation during prograde metamorphism
- High-pressure phase transitions in MgSiO3 orthoenstatite studied by atomistic computer simulation
- Time-resolved synchrotron powder X-ray diffraction study of magnetite formation by the Fe(III)-reducing bacterium Geobacter sulfurreducens
- Low-temperature calorimetric and magnetic data for natural end-members of the axinite group
- Temperature derivatives of elastic wave velocities in plagioclase (An51±1) above and below the order-disorder transition temperature
- Disordered silica with tridymite-like structure in the Twiggs clay
- Crystal structures of synthetic melanotekite (Pb2Fe2Si2O9), kentrolite (Pb2Mn2Si2O9), and the aluminum analogue (Pb2Al2Si2O9)
- Structure and reactivity of synthetic Co-substituted goethites
- The crystal chemistry of Fe-bearing sphalerites: An infrared spectroscopic study
- Effects of hydration on the structure and compressibility of wadsleyite, β-(Mg2SiO4)
- Metastability of sillimanite relative to corundum and quartz in the kyanite stability field: Competition between stable and metastable reactions
- Diffusion, discontinuous precipitation, metamorphism, and metasomatism: The complex history of South African upper-mantle symplectites
- Thermal behavior of a Ti-rich phlogopite from Mt. Vulture (Potenza, Italy): An in situ X-ray single-crystal diffraction study
- The high-pressure behavior of an Al- and Fe-rich natural orthopyroxene
- High-pressure phase relation of MnSiO3 up to 85 GPa: Existence of MnSiO3 perovskite
- Linking Mössbauer and structural parameters in elbaite-schorl-dravite tourmalines
- Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of palygorskite
- Maskelynite-hosted apatite in the Chassigny meteorite: Insights into late-stage magmatic volatile evolution in martian magmas
- Eskolaite associated with diamond from the Udachnaya kimberlite pipe, Yakutia, Russia
- Lakebogaite, CaNaFe23+H(UO2)2(PO4)4(OH)2(H2O)8, a new uranyl phosphate with a unique crystal structure from Victoria, Australia
- Letter. Crystal structure and Raman spectrum of hydroxyl-bästnasite-(Ce), CeCO3(OH)
Artikel in diesem Heft
- Compositional variability and crystal structural features of guanacoite
- Interferometric study of pyrite surface reactivity in acidic conditions
- White mica domain formation: A model for paragonite, margarite, and muscovite formation during prograde metamorphism
- High-pressure phase transitions in MgSiO3 orthoenstatite studied by atomistic computer simulation
- Time-resolved synchrotron powder X-ray diffraction study of magnetite formation by the Fe(III)-reducing bacterium Geobacter sulfurreducens
- Low-temperature calorimetric and magnetic data for natural end-members of the axinite group
- Temperature derivatives of elastic wave velocities in plagioclase (An51±1) above and below the order-disorder transition temperature
- Disordered silica with tridymite-like structure in the Twiggs clay
- Crystal structures of synthetic melanotekite (Pb2Fe2Si2O9), kentrolite (Pb2Mn2Si2O9), and the aluminum analogue (Pb2Al2Si2O9)
- Structure and reactivity of synthetic Co-substituted goethites
- The crystal chemistry of Fe-bearing sphalerites: An infrared spectroscopic study
- Effects of hydration on the structure and compressibility of wadsleyite, β-(Mg2SiO4)
- Metastability of sillimanite relative to corundum and quartz in the kyanite stability field: Competition between stable and metastable reactions
- Diffusion, discontinuous precipitation, metamorphism, and metasomatism: The complex history of South African upper-mantle symplectites
- Thermal behavior of a Ti-rich phlogopite from Mt. Vulture (Potenza, Italy): An in situ X-ray single-crystal diffraction study
- The high-pressure behavior of an Al- and Fe-rich natural orthopyroxene
- High-pressure phase relation of MnSiO3 up to 85 GPa: Existence of MnSiO3 perovskite
- Linking Mössbauer and structural parameters in elbaite-schorl-dravite tourmalines
- Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of palygorskite
- Maskelynite-hosted apatite in the Chassigny meteorite: Insights into late-stage magmatic volatile evolution in martian magmas
- Eskolaite associated with diamond from the Udachnaya kimberlite pipe, Yakutia, Russia
- Lakebogaite, CaNaFe23+H(UO2)2(PO4)4(OH)2(H2O)8, a new uranyl phosphate with a unique crystal structure from Victoria, Australia
- Letter. Crystal structure and Raman spectrum of hydroxyl-bästnasite-(Ce), CeCO3(OH)