In situ hot-stage AFM study of the dissolution of the barite (001) surface in water at 30–55 °C
-
Yoshihiro Kuwahara
Abstract
This paper reports in situ observations of the dissolution behavior of the barite (001) surface in pure water at 30-55 °C using hot-stage atomic force microscopy (AFM). The dissolution at 30 and 40 °C occurred in three stages; however, at 55 °C, the dissolution behavior observed at the former temperatures started immediately after injecting water into the AFM fluid cell. The first stage of the dissolution was characterized by the retreat of the initial steps and continued for about 60 min at 30 °C and about 10 min at 40 °C. The second stage of the dissolution was characterized by the splitting of the initial <hk0> one-layer step into two half-layer steps [fast (“f”) and slow (“s”) retreat steps] with different retreat rates and by the formation of etch pits. The large difference in the retreat rate of the “f” and “s” steps led to the formation of a new one-layer step, which showed slightly faster retreat rates than the “s” half-layer step at all temperatures. The splitting of the [010] one-layer step into two half-layer steps was observed only at 55 °C. During the third stage, the development of angular deep etch pits from an initial form with a curved outline differed at each temperature. The deep etch pits grew rapidly at higher temperature, but showed at least two different retreat rates for the (001) plane at each temperature, indicating the development of the pits along different dislocations (screw and edge dislocations).
The activation energies (62-74 kJ/mol) for the step and face retreats in this study were significantly higher than those reported in earlier studies. Recalculations performed using only data obtained under similar conditions in previous studies led to activation energies of 66-79 kJ/mol. These results and the earlier report showing that the form of the deep etch pits changed from angular to bow-shaped at about 60 °C may indicate that the activation energy of barite dissolution in water is higher at lower temperatures as compared with higher temperatures, thus changing the rate-limiting step. Whether the vertical and lateral retreat rates of the barite (001) plane differ in dependence of temperature remains unclear; however, the activation energies of the retreat of the (001) face in deep etch pits tended to be slightly higher than that of the lateral retreat rates of steps or other faces in deep etch pits.
© 2015 by Walter de Gruyter Berlin/Boston
Artikel in diesem Heft
- MSA Roebling medal lecture. Mineralogy, petrology, U-Pb geochronology, and geologic evolution of the Dabie-Sulu classic ultrahigh-pressure metamorphic terrane, East-Central China
- Brittle-ductile microfabrics in naturally deformed zircon: Deformation mechanisms and consequences for U-Pb dating
- In situ hot-stage AFM study of the dissolution of the barite (001) surface in water at 30–55 °C
- A multi-domain gem-grade Brazilian apatite
- High-temperature structural behaviors of anhydrous wadsleyite and forsterite
- Rates and mechanism of Y, REE, and Cr diffusion in garnet
- EPR discrimination of microcrystalline calcite geomaterials
- Crystal chemistry of Bi- and Mn-bearing vesuvianite from Långban, Sweden
- Cation ordering in Pb2+-bearing, Mn3+-rich pargasite from Långban, Sweden
- Long-term solid-phase fate of co-precipitated U(VI)-Fe(III) following biological iron reduction by Thermoanaerobacter
- The sulfur speciation in S-bearing minerals: New constraints by a combination of electron microprobe analysis and DFT calculations with special reference to sodalite-group minerals
- Simultaneous sound velocity and density measurements of NaCl at high temperatures and pressures: Application as a primary pressure standard
- The temperature and compositional dependence of disordering in Fe-bearing dolomites
- Quantifying crystallization and devitrification of rhyolites by means of X-ray diffraction and electron microprobe analysis
- Reactions of strontium anorthite with H2O+CaCl2 fluids at 500 °C and high pressure: Kinetic information from in situ synchrotron-radiation XRF analyses of the fluid
- Solubility of xenotime in a 2 M HCl aqueous fluid from 1.2 to 2.6 GPa and 300 to 500 °C
- Elastic and anelastic anomalies due to spin-state transitions in orthorhombic perovskite from isoelectronic behavior of Co3+ and Fe2+
- Accurate determination of ferric iron in garnets by bulk Mössbauer spectroscopy and synchrotron micro-XANES
- Re-investigation of the crystal structure of enstatite under high-pressure conditions
- Second-order P6̄c2-P31c transition and structural crystallography of the cyclosilicate benitoite, BaTiSi3O9, at high pressure
- High-pressure structural studies of eskolaite by means of single-crystal X-ray diffraction
- Almandine: Lattice and non-lattice heat capacity behavior and standard thermodynamic properties
- Witzkeite: A new rare nitrate-sulphate mineral from a guano deposit at Punta de Lobos, Chile
- Krasheninnikovite, KNa2CaMg(SO4)3F, a new mineral from the Tolbachik volcano, Kamchatka, Russia
- Crystal structure of pseudojohannite, with a revised formula, Cu3(OH)2[(UO2)4O4(SO4)2](H2O)12
- Letter. A natural photoelectrochemical cell for water splitting: Implications for early Earth and Mars
- Letter. In situ observation of the breakdown of magnetite (Fe3O4) to Fe4O5 and hematite at high pressures and temperatures
- Letter. The crystal structure of bartelkeite, with a revised chemical formula, PbFeGeVI(Ge2IVO7) (OH)2·H2O, isotypic with high-pressure P21/m lawsonite
Artikel in diesem Heft
- MSA Roebling medal lecture. Mineralogy, petrology, U-Pb geochronology, and geologic evolution of the Dabie-Sulu classic ultrahigh-pressure metamorphic terrane, East-Central China
- Brittle-ductile microfabrics in naturally deformed zircon: Deformation mechanisms and consequences for U-Pb dating
- In situ hot-stage AFM study of the dissolution of the barite (001) surface in water at 30–55 °C
- A multi-domain gem-grade Brazilian apatite
- High-temperature structural behaviors of anhydrous wadsleyite and forsterite
- Rates and mechanism of Y, REE, and Cr diffusion in garnet
- EPR discrimination of microcrystalline calcite geomaterials
- Crystal chemistry of Bi- and Mn-bearing vesuvianite from Långban, Sweden
- Cation ordering in Pb2+-bearing, Mn3+-rich pargasite from Långban, Sweden
- Long-term solid-phase fate of co-precipitated U(VI)-Fe(III) following biological iron reduction by Thermoanaerobacter
- The sulfur speciation in S-bearing minerals: New constraints by a combination of electron microprobe analysis and DFT calculations with special reference to sodalite-group minerals
- Simultaneous sound velocity and density measurements of NaCl at high temperatures and pressures: Application as a primary pressure standard
- The temperature and compositional dependence of disordering in Fe-bearing dolomites
- Quantifying crystallization and devitrification of rhyolites by means of X-ray diffraction and electron microprobe analysis
- Reactions of strontium anorthite with H2O+CaCl2 fluids at 500 °C and high pressure: Kinetic information from in situ synchrotron-radiation XRF analyses of the fluid
- Solubility of xenotime in a 2 M HCl aqueous fluid from 1.2 to 2.6 GPa and 300 to 500 °C
- Elastic and anelastic anomalies due to spin-state transitions in orthorhombic perovskite from isoelectronic behavior of Co3+ and Fe2+
- Accurate determination of ferric iron in garnets by bulk Mössbauer spectroscopy and synchrotron micro-XANES
- Re-investigation of the crystal structure of enstatite under high-pressure conditions
- Second-order P6̄c2-P31c transition and structural crystallography of the cyclosilicate benitoite, BaTiSi3O9, at high pressure
- High-pressure structural studies of eskolaite by means of single-crystal X-ray diffraction
- Almandine: Lattice and non-lattice heat capacity behavior and standard thermodynamic properties
- Witzkeite: A new rare nitrate-sulphate mineral from a guano deposit at Punta de Lobos, Chile
- Krasheninnikovite, KNa2CaMg(SO4)3F, a new mineral from the Tolbachik volcano, Kamchatka, Russia
- Crystal structure of pseudojohannite, with a revised formula, Cu3(OH)2[(UO2)4O4(SO4)2](H2O)12
- Letter. A natural photoelectrochemical cell for water splitting: Implications for early Earth and Mars
- Letter. In situ observation of the breakdown of magnetite (Fe3O4) to Fe4O5 and hematite at high pressures and temperatures
- Letter. The crystal structure of bartelkeite, with a revised chemical formula, PbFeGeVI(Ge2IVO7) (OH)2·H2O, isotypic with high-pressure P21/m lawsonite
