High-temperature structural behaviors of anhydrous wadsleyite and forsterite
-
Dmytro M. Trots
,
Alexander Kurnosov
Abstract
The thermal expansion of anhydrous Mg2SiO4 wadsleyite and forsterite was comprehensively studied over the temperature ranges 297-1163 and 297-1313 K, respectively, employing X-ray powder diffraction. Experiments were carried out with two separately synthesized samples of wadsleyite (numbered z626 and z627), for which room temperature unit-cell volumes differed by 0.05%, although the determined thermal expansions were identical within error. The high-temperature thermal expansions of wadsleyite and forsterite were parameterized on the basis of the first-order Grüneisen approximation using a Debye function for the internal energy. Values for hypothetical volume at T = 0 K, Debye temperature and Grüneisen parameter are 536.86(14) Å3, 980(55) K, 1.28(2) and 537.00(13) Å3, 887(50) K, 1.26(1) for z626 and z627, respectively, with the bulk modulus fixed to a literature determination of 161 GPa. For forsterite, the respective values are 288.80(2) Å3, 771(9) K, and 1.269(2) with a constrained bulk modulus of 125 GPa. These quantities are in good agreement with literature values obtained independently from sound velocity and heat capacity measurements, giving strong support to the applicability of Grüneisen theory in describing the thermal expansion of wadsleyite and forsterite. In addition, high-temperature structural variations were determined for wadsleyite from Rietveld analysis of the X-ray diffraction data. The pronounced anisotropy in thermal expansion of wadsleyite with a more expandable c-axis, similar to the compressional anisotropy, arises from specific features of the crystal structure consisting of the pseudolayers of MgO6 octahedra parallel to the a-b plane with cross-linking Si2O7 dimers along the c-axis. Although anisotropic compression and expansion originate from the same structural features, the details of structural changes with pressure differ from those caused by temperature. The longest Mg-O bonds, which are roughly parallel to the c-axis in all three octahedral sites of wadsleyite, dominate the compression, but these bonds do not exhibit the largest expansivities.
© 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
