Investigation of the {104} surface of calcite under dry and humid atmospheric conditions with grazing incidence X-ray diffraction (GIXRD)

Magdans, Uta; Gies, Hermann; Torrelles, X.; Rius, Jordi

doi:10.1127/0935-1221/2006/0018-0083

Cited by 32 publications

(53 citation statements)

References 18 publications

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“…At 100% coverage a zig-zag pattern of water formed, this is consistent with previous classical simulations [6] and X-ray experiments [77]. During an MD simulation at 200% coverage the zig-zag pattern was lost and no new pattern was established in its place.…”

Section: Discussionsupporting

confidence: 78%

“…This pattern had previously been obtained using classical simulations [6] and X-ray experiments are consistent with the view that water forms this pattern on the {1014} calcite surface [77].…”

Section: Discussionsupporting

confidence: 70%

“…This pattern has previously been observed in classical MD simulations by de Leeuw and Parker [6]. GIXRD (grazing incidence x-ray diffraction) data taken by Magdans et al was later fitted to the surface model found by de Leeuw and Parker and found to be consistent with this surface water pattern [77]. The zig-zag stucture was relaxed in a static calculation.…”

Section: Simulation At 100% Water Coveragementioning

confidence: 59%

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Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

2009

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Density functional theory calculations were employed to explore the interaction between water and the {1014} surface of calcite. In addition a defective {1014} surface and stepped surfaces in contact with water were investigated. A series of percentage water coverages and water configurations were explored, including dissociated water states. Static relaxations found associated water to be favourable on the {1014} surface, although a metastable dissociated state 1.77eV higher in energy was found.Molecular dynamics (MD) simulations of low water coverage reveal fluctuations in the H-O water bond when the H atom is directed towards a surface CO 3 ion. Desorption of an H 2 O molecule was observed in simulations above 900K. Water was found to be strongly bound to the perfect {1014} surface, with an adsorption energy of -0.91eV. MD simulations of a defective {1014} surface found water to favour dissociation at CO 3 vacancies. However, water at Ca vacancies diffused across the surface to form a bond with the nearest surface Ca ion. Water was also found to favour an associated state at both acute and obtuse steps. On all these imperfect surfaces water was found to adsorb strongly to the surface, with adsorption energies ranging from -0.99eV to -1.60eV.

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Section: Discussionsupporting

confidence: 78%

Section: Discussionsupporting

confidence: 70%

Section: Simulation At 100% Water Coveragementioning

confidence: 59%

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Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

2009

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“…Numerous surface-sensitive instrumental techniques have been employed to characterize the (10.4) calcite surface under wet and/or vacuum conditions, such as X-ray Photoelectron Spectroscopy (XPS, Stipp and Hochella, 1991;Stipp, 1999), Low Energy Electron Diffraction (LEED, Stipp and Hochella, 1991;Stipp, 1999), Time-OfFlight Secondary Ion Mass Spectroscopy (TOF-SIMS, Stipp, 1999), Infrared Spectroscopy (IR, Neagle and Rochester, 1990), Fourier Transform Infrared Spectroscopy (FTIR, Kuriyavar et al, 2000), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT, Pokrovsky et al, 2000), Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR, AlHosney and Grassian, 2005), Atomic Force Microscopy (AFM, Rachlin et al, 1992;Stipp et al, 1994;Liang et al, 1996;Stipp, 1999), X-ray Reflectivity and Scattering (SXR, Chiarello et al, 1993;Fenter et al, 2000;Geissbü hler et al, 2004), and Grazing Incidence X-ray Diffraction (GIXRD, Magdans et al, 2006). These techniques revealed that the outer-most atomic layer relaxes and the surface undergoes a certain degree of reconstruction upon hydration.…”

Section: Rhombohedral Carbonate Mineralsmentioning

confidence: 98%

Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals

Villegas-Jiménez

Mucci

Pokrovsky

et al. 2009

Geochimica et Cosmochimica Acta

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“…In the case of metal oxides (CaO, MgO, and Fe 2 O 3 ) and carbonates (CaCO 3 and MgCO 3 ), dissociation of water molecules at the interfaces is energetically favorable because hydroxylated surfaces are more stable than metal-terminated surfaces under ambient conditions (15,41,42). Recent experiments and molecular dynamic simulations have shown the free energy of adsorption of water on calcite surfaces (43,44) to be as low as −10.6 kcal mol −1 .…”

Section: Discussionmentioning

confidence: 99%

Detection of oxygen isotopic anomaly in terrestrial atmospheric carbonates and its implications to Mars

Shaheen

Abramian

Horn

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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The debate of life on Mars centers around the source of the globular, micrometer-sized mineral carbonates in the ALH84001 meteorite; consequently, the identification of Martian processes that form carbonates is critical. This paper reports a previously undescribed carbonate formation process that occurs on Earth and, likely, on Mars. We identified micrometer-sized carbonates in terrestrial aerosols that possess excess 17 O (0.4-3.9‰). The unique O-isotopic composition mechanistically describes the atmospheric heterogeneous chemical reaction on aerosol surfaces. Concomitant laboratory experiments define the transfer of ozone isotopic anomaly to carbonates via hydrogen peroxide formation when O 3 reacts with surface adsorbed water. This previously unidentified chemical reaction scenario provides an explanation for production of the isotopically anomalous carbonates found in the SNC (shergottites, nakhlaites, chassignites) Martian meteorites and terrestrial atmospheric carbonates. The anomalous hydrogen peroxide formed on the aerosol surfaces may transfer its O-isotopic signature to the water reservoir, thus producing mass independently fractionated secondary mineral evaporites. The formation of peroxide via heterogeneous chemistry on aerosol surfaces also reveals a previously undescribed oxidative process of utility in understanding ozone and oxygen chemistry, both on Mars and Earth.nanoparticles | mineral dust | heterogeneous chemical transformation | surface chemistry | mass-independent fractionation T he search for life beyond Earth is pursued based upon the requirement of liquid water both as a solvent and transport medium, and its biochemically unique role in providing support to cell structure (1). Central to the question of potential life on Mars is whether liquid water ever existed on the surface of Mars and, if so, under what climatic conditions (2). Apart from satellite observations of valleys and channels formed by aqueous activity, there are few quantitative measures (e.g., Thermal and Electrical Conductivity probe on Phoenix Lander; Compact Reconnaissance Imaging Spectrometer for Mars; High Energy Neutron Detector on board Mars Odyssey spacecraft) of significant amounts of liquid water at the surface of Mars today (3-5). Secondary minerals such as carbonates and sulfates record physicalchemical settings of the environment in which they are formed and geochemical relations between the atmosphere and the Martian surface (6). Unlike terrestrial carbonate sediments, the Martian surface lacks large amounts of carbonates despite a CO 2 -rich (95% vol∕vol) atmosphere, though, there is evidence of Mg-Fe rich carbonates (16-34 wt %) in the Columbia Hills and <5% CaCO 3 in Martian dust and soils (3,(7)(8)(9). In contrast to most Martian meteorites, ALH84001 contained substantial amounts of secondary carbonate minerals with an average age of 3.90 AE 0.04 billion years, contemporaneous with a wet period in Martian history (10). The formation of well-defined globular structures of a definite size range and their a...

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Investigation of the {104} surface of calcite under dry and humid atmospheric conditions with grazing incidence X-ray diffraction (GIXRD)

Cited by 32 publications

References 18 publications

Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

Investigation of the Interaction of Water with the Calcite (10.4) Surface Using Ab Initio Simulation

Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals

Detection of oxygen isotopic anomaly in terrestrial atmospheric carbonates and its implications to Mars

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