Iron concentration and the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass
-
Glen B. Cook
and
Reid F. Cooper
Abstract
Rutherford backscattering spectroscopy was used to investigate the persistence of cation-diffusion- limited oxidation in three, low-Fe2+-bearing MgO-Al2O3-SiO2 glasses (base glass compositions along the enstatite-cordierite-liquid cotectic; total Fe levels of 0.04, 0.19, and 0.54 at%). The glasses were reacted in air at temperatures of 700-850 °C (~Tg), and changes in the composition of the nearsurface region (≤2.5 μm) of the glass resulting from oxidation were characterized. The reaction morphology produced by oxidation at temperatures above 800 °C, for all of the glasses studied regardless of Fe concentration, was consistent uniquely with an oxidation process dominated by diffusion of Fe2+ cations to the free surface that was charge compensated by a (counter) flux of electron holes into the material. In the high-Fe material (0.54 at%), the activation energy for the cation-diffusion-limited reaction was estimated at ~475 kJ/mol. Below 800 °C, the two glasses with lowest Fe concentration displayed a reaction morphology consistent with oxidation occurring by the motion of an oxygen species. High levels of transition metal cations are not required to ensure the dominance of cation-diffusion-limited oxidation reaction in silicate glasses and melts; thus, monitoring internal Fe3+:Fe2+ equilibrium, even at trace amounts, seems untenable as an indicator of the diffusion behavior of molecular or ionic oxygen.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Iron concentration and the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass
- A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies
- Mineralogy of mafic xenoliths and their reaction zones in the olivine lamproite from Prairie Creek Arkansas and the paragenesis of haggertyite, Ba [Fe6Ti5Mg]O19
- Magmatic anhydrite in granitic rocks: First occurrence and potential petrologic consequences
- Crystal chemistry of Al-rich biotites coexisting with muscovites in peraluminous granites
- Spectroscopic and structural properties of synthetic micas on the annite-siderophyllite binary: Synthesis, crystal structure refinement, Mössbauer, and infrared spectroscopy
- Thermodynamic properties of tremolite: A correction and some comments
- Raman spectroscopic characteristics of Mg-Fe-Ca pyroxenes
- Hydrogen in diopside: Diffusion profiles
- Diffusion of C and O in calcite at 100 MPa
- Solubility and stability of zeolites in aqueous solution: II. Calcic clinoptilolite and mordenite
- TEM and SFM of exsolution and twinning in an alkali feldspar
- Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure
- Optimization of site occupancies in minerals using quadratic programming
- Leverage analysis and structure refinement of minerals
- The absolute energy positions of conduction and valence bands of selected semiconducting minerals
- Antiferroelectric phase transition in titanite: Excess entropy and short range order
- P4/n and P4nc long-range ordering in low-temperature vesuvianites
- Tetrahedral vacancies and cation ordering in low-temperature Mn-bearing vesuvianites: Indication of a hydrogarnet-like substitution
- Sodic-ferripedrizite, a new monoclinic amphibole bridging the magnesium-iron-manganese-lithium and the sodium-calcium groups
- The crystal structure of peprossiite-(Ce), an anhydrous REE and Al mica-like borate with square-pyramidal coordination for Al
- Crystal chemistry of the new mineral brandholzite, Mg(H2O)6[Sb(OH)6]2, and of the synthetic analogues M2+(H2O)6[Sb(OH)6]2 (M2+ = Mg, Co)
- Letters. In-situ Raman spectra of dissolved silica species in aqueous fluids to 900 °C and 14 kbar
- Quetzalcoatlite: A new octahedral-tetrahedral structure from a 2 × 2 × 40 μm3 crystal at the Advanced Photon Source-GSE-CARS Facility
- Bonding and dynamics of Mg in pyrope: a theoretical investigation
- Structure of a new Al-rich phase, [K, Na]0.9[Mg, Fe]2[Mg, Fe, Al, Si]6O12, synthesized at 24 GPa
- Core level electron binding energies of realgar (As4S4)
- Oxidation of {100} and {111} surfaces of pyrite: Effects of preparation method
Articles in the same Issue
- Iron concentration and the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass
- A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies
- Mineralogy of mafic xenoliths and their reaction zones in the olivine lamproite from Prairie Creek Arkansas and the paragenesis of haggertyite, Ba [Fe6Ti5Mg]O19
- Magmatic anhydrite in granitic rocks: First occurrence and potential petrologic consequences
- Crystal chemistry of Al-rich biotites coexisting with muscovites in peraluminous granites
- Spectroscopic and structural properties of synthetic micas on the annite-siderophyllite binary: Synthesis, crystal structure refinement, Mössbauer, and infrared spectroscopy
- Thermodynamic properties of tremolite: A correction and some comments
- Raman spectroscopic characteristics of Mg-Fe-Ca pyroxenes
- Hydrogen in diopside: Diffusion profiles
- Diffusion of C and O in calcite at 100 MPa
- Solubility and stability of zeolites in aqueous solution: II. Calcic clinoptilolite and mordenite
- TEM and SFM of exsolution and twinning in an alkali feldspar
- Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure
- Optimization of site occupancies in minerals using quadratic programming
- Leverage analysis and structure refinement of minerals
- The absolute energy positions of conduction and valence bands of selected semiconducting minerals
- Antiferroelectric phase transition in titanite: Excess entropy and short range order
- P4/n and P4nc long-range ordering in low-temperature vesuvianites
- Tetrahedral vacancies and cation ordering in low-temperature Mn-bearing vesuvianites: Indication of a hydrogarnet-like substitution
- Sodic-ferripedrizite, a new monoclinic amphibole bridging the magnesium-iron-manganese-lithium and the sodium-calcium groups
- The crystal structure of peprossiite-(Ce), an anhydrous REE and Al mica-like borate with square-pyramidal coordination for Al
- Crystal chemistry of the new mineral brandholzite, Mg(H2O)6[Sb(OH)6]2, and of the synthetic analogues M2+(H2O)6[Sb(OH)6]2 (M2+ = Mg, Co)
- Letters. In-situ Raman spectra of dissolved silica species in aqueous fluids to 900 °C and 14 kbar
- Quetzalcoatlite: A new octahedral-tetrahedral structure from a 2 × 2 × 40 μm3 crystal at the Advanced Photon Source-GSE-CARS Facility
- Bonding and dynamics of Mg in pyrope: a theoretical investigation
- Structure of a new Al-rich phase, [K, Na]0.9[Mg, Fe]2[Mg, Fe, Al, Si]6O12, synthesized at 24 GPa
- Core level electron binding energies of realgar (As4S4)
- Oxidation of {100} and {111} surfaces of pyrite: Effects of preparation method
